Kate, who is in remission after being diagnosed with cancer in 2024, addresses those affected by the disease, telling them: "Please know that you are not alone."
She tells how a cancer journey has "moments of fear and exhaustion" but also "moments of strength, kindness, and profound connection".
Epstein latest - claims of threesome with Andrew and stripper
It is accompanied by footage of her visiting the Royal Marsden Hospital in London last January, on the day she confirmed she was in remission.
Cancer, she says, touches "so many lives. Not only patients, but the families and friends and caregivers who walk beside them. As anyone who has experienced this journey will know, it's not linear".
World Cancer Day, she adds, is "a reminder of the importance of care, understanding and hope".
Kate has been carrying out more regular engagements recently after slowly easing back into her public royal duties over the past year and a half.
On Tuesday, she made a solo visit to west Wales, where a well-wisher outside Hiut Denim, a family-owned jeans manufacturer based in Cardigan, told her, "I hope you're getting better really soon after what happened to you."
She replied: "Thank you very much. This is good for my soul meeting wonderful people."
The King also posted his own video to mark the day in which he said that he had been "profoundly moved" by the "community of care that surrounds every cancer patient" following his own diagnosis.
In a message on the Royal Family's Instagram account, Charles pointed to the specialists, nurses, researchers and volunteers who "work tirelessly to save and improve lives".
A message accompanying the video said to "all those who care for patients and families and to everyone who offers support in ways seen and unseen - we thank you".
The King, who was diagnosed with cancer in February 2024, revealed in December that his cancer treatment can be reduced this year.
Read more on Sky News:
'Bold' new cancer strategy
More baby formula recalled
In a separate video message last year, the King said his "good news" was "thanks to early diagnosis, effective intervention and adherence to doctors' orders".
He called it "a personal blessing and a testimony to the remarkable advances that have been made in cancer care in recent years".
Police were called just after 5pm on Tuesday following a report a man had collapsed in Oxford Street, close to the junction with Bonners Lane, near De Montfort University.
While officers were on their way to the scene, it was reported the victim - aged in his 20s - had been stabbed, Leicestershire Police said.
He was taken to Leicester Royal Infirmary where he died a short time later, the force added.
De Montfort University said the victim was one of its students.
The university's vice-chancellor, Professor Katie Normington, said: "We are devastated to confirm the tragic death of one of our students.
"Our thoughts are with everyone who is affected by what has happened.
"We are offering direct support to students, staff and the family of the victim."
Police said it is believed the victim was involved in an altercation with another man in the street, who left the scene before officers arrived.
Read more from Sky News:
Snooker legend John Virgo dies
Baby formula recalled due to toxin
Detective Inspector Lorna Granville said: "CCTV in the area is currently being reviewed and officers are speaking to potential witnesses to assist with our investigation.
"We know a lot of people came to the aid of the victim before emergency services arrived and we want to thank them for their help.
"If you were one of these people and you haven't yet spoken to police, please make contact with us.
"We know the area was also busy with motorists driving along Oxford Street.
"If you saw anything or captured footage on dash cam as you drove past the area we would also like to hear from you."
They include Taskmaster stars Ania Magliano and Emma Sidi, Black Ops star Hammed Animashaun, and Ayoade Bamgboye, who was named best newcomer at the Edinburgh Comedy Awards last year.
Larry Dean, who has appeared on Live At The Apollo, and Celeste Dring, whose credits include This Country and Lazy Susan, also feature in the SNL UK cast of 11, along with Paddy Young (Everyone Else Burns and Mitchell & Webb Are Not Helping) and "Instagram heartthrob" Al Nash.
George Fouracres (Steve), Jack Shep (Big Boys) and Annabel Marlow (Six The Musical) complete the line-up, billed as the "new generation" of British comedians.
SNL, broadcast on NBC in the US, is an American pop culture institution which has been running for 50 years, and launched the careers of stars including Bill Murray, Tina Fey, Eddie Murphy, Pete Davidson, Kristen Wiig and Will Ferrell.
The first UK version is set to launch on Sky in March, with a guest host helming the show each week.
Star hosts in the US last year included Sabrina Carpenter, Ariana Grande, Josh O'Connor, Glen Powell, Golden Globes presenter Nikki Glaser and recent Grammy winner Bad Bunny.
"I just love sketch comedy," said Dean, on why he wanted to join the show. "There have been so many people who have appeared on Saturday Night Live, either as hosts or part of the cast, that are my comedy heroes - like Jim Carrey, Richard Pryor, Mike Myers, Dana Carvey."
Fouracres said he had often watched clips of the US show and thought, "I wish we had that. Why don't we have something like that?"
Being part of the new show "blows my tiny mind", he added.
Producers announced the UK show's creative team in November and have said writers will also be revealed soon.
Written, rehearsed and performed in the week of each show, every episode will be staged in front of a live studio audience and feature an opening monologue, topical sketches, live music, and a UK take on SNL's famous news satire, Weekend Update.
Lead producer James Longman said the UK cast members represent "the freshest voices we have" and are "bold, exciting and of course, incredibly funny".
Read more:
The Ozzy tape found in an attic after 46 years
KPop Demon Hunters singers to perform at BAFTAs
The UK show will be overseen by US producer Lorne Michaels.
Phil Edgar Jones, executive director for unscripted originals at Sky, said the time is right for the show as "we all need a laugh like never before".
"The show's long-standing legacy of discovering and nurturing outstanding comedy talent speaks for itself, and this UK version will build on that legacy with the support of Lorne Michaels, a brilliant local production team, and an exciting new generation of voices," he said.
Saturday Night Live UK will be broadcast on Sky and streaming service NOW from 21 March.
The last remaining treaty capping the arsenals of Russia and the US will expire on Thursday.
It means, for the first time in more than half a century, there will be no legal limits on their missiles and warheads, and there are fears we are on the brink of a new arms race.
"It's a serious situation," Vasily Kashin, a research fellow at Moscow's Higher School of Economics, told Sky News.
"Probably now we can witness a lot of developments, especially in the US nuclear policy, and the situation will be quite unpredictable.
"There is a real danger of a nuclear arms race in the coming years."
The first agreement on arms control between the world's nuclear superpowers was in 1972, signed by US president Richard Nixon and Soviet leader Leonid Brezhnev.
The aim was to slow the arms race and prevent a catastrophic misunderstanding.
Even at the height of the Cold War, these two rivals could agree on that.
In 1991, as the Soviet Union fell, George Bush senior and Mikhail Gorbachev signed the START treaty.
It was the first time both sides had to reduce their arsenals and it marked the start of an inspection framework, so that each side could check the other was complying with the limits.
The most recent treaty - the New START - was signed in 2010, by Barack Obama and Dmitry Medvedev, before being extended for five years in 2021.
On each side, the number of deployed strategic warheads are capped at 1,550, and the number of delivery vehicles are limited to 700.
That's more than enough for Russia and the US to destroy each other but it's a cap nonetheless.
And when this treaty expires on Thursday, that cap will no longer exist, ending decades of arms control cooperation.
So how have we reached this point?
The Kremlin's invasion of Ukraine in 2022 saw a breakdown in Russia-US relations, to the point where talks to negotiate a new treaty were never even scheduled.
The terms of the current treaty allow only for one formal extension.
Vladimir Putin has proposed an informal rollover for 12 months, but Donald Trump so far hasn't agreed.
Some believe he's crazy not to, fearing the US will be the one that loses out if there is an arms race.
Read more: Doomsday Clock closer to midnight than ever
But others believe it's a good move, leaving America free to compete with the nuclear build-up of other countries like China.
And China's clearly on the US president's mind - he says he wants a new trilateral treaty that includes Beijing.
But those who've worked on these things warn that it's wishful thinking.
"We never tried trilateral [talks] actually," Nikolai Sokov, a former Soviet and Russian arms control negotiator, told Sky News.
"Who says it's going to be trilateral? The official Russian position and the official Chinese position is that negotiations can be bilateral between the United States and Russia, or they can be five-party, including the United Kingdom and France."
So barring any last-minute deal, we're entering unchartered territory and who knows for how long.
The strategic stability won't change overnight but the absence of any agreement shows how far US-Russia relations have fallen.
And it could make the world a much more dangerous place.
Marius Borg Hoiby, 29, son of Crown Princess Mette-Marit and stepson to Crown Prince Haakon, could face years in prison if found guilty of the most serious of the 38 charges against him.
The case has shaken the Norwegian royal family, which has historically enjoyed high favourability ratings.
On Tuesday, the first day of his trial, he pleaded not guilty to the most serious charges of rape and domestic violence, but admitted some lesser charges, including driving too fast.
He also said he was partially guilty - a plea allowed under Norwegian law - of aggravated assault and reckless behaviour.
On Wednesday, Hoiby broke down in tears during his first day on the witness stand, saying: "It is very difficult for me to speak in front of so many people.
"I have been surrounded by the press since I was three. I have been harassed ever since."
He said he had received "heavy medication", and would try to do as much as he could.
Hoiby spoke about growing up as the son of a crown princess.
He said: "I have an extreme need for affirmation. A lot of sex, a lot of alcohol. Few can relate to the life I have led. A lot of parties, alcohol, some drugs."
Hoiby wore jeans and a dark blue jumper over a beige shirt, and spoke with his arms crossed, occasionally consulting handwritten notes from a notebook.
Some of the most serious charges against Hoiby are one count of rape with sexual intercourse, and three counts of rape without intercourse, some of which the prosecution says he filmed on his telephone.
He denied the videos on his phone show acts of rape, and noted that he had never shared them with anyone.
"If I had thought I had material that showed an assault, I would never have kept that material," he said.
Read more from Sky News:
Murder investigation launched after student stabbed in Leicester
Teenage boy swims for four hours to save family
Hoiby's trial is scheduled to run until 19 March, and prosecutors have said that he could face up to 10 years in prison if convicted.
The crown prince and princess do not plan to attend the trial of Hoiby, who is outside the line of royal succession and has no title.
A monarchy under pressure
The trial comes as the Norwegian royal family is facing challenges on multiple fronts.
Hoiby's mother, Crown Princess Mette-Marit, is under intense scrutiny over her ties with the late sex offender Jeffrey Epstein.
An opinion poll conducted on Monday for daily newspaper Verdens Gang, showed only 61% of Norwegians were in favour of keeping the monarchy - a drop of 11%.