Prince William has become the first royal to publicly acknowledge the cancer diagnosis of his father, King Charles.
William thanked the British public for their well wishes while at a gala event in London.
The Prince of Wales had been attending an event in support of London's Air Ambulance Charity on Wednesday night (UK time) when he made the comments.
As he was walking into the event, he was asked about his father and told reporters "we really appreciate everyone's kindness" before posing for photos with Hollywood actor Tom Cruise, who was also there.
It is believed Cruise is a supporter of London's Air Ambulance.
On Tuesday, Buckingham Palace announced the King had been diagnosed with the disease, but didn't state anything further about his condition.
The palace released a statement saying during the King's recent time in hospital to undergo a corrective procedure for an enlarged prostate, a "separate issue of concern" was found.
"Subsequent diagnostic tests have identified a form of cancer," the statement said.
William has also been dealing with the after-effects of his wife, the Princess of Wales, who has recently undergone abdominal surgery. That was for a non-specified but non-cancerous condition at the London Clinic earlier in January.
Her Kensington Palace office said she was making "good progress" and she was now back at home in Windsor.
Meanwhile, UK tabloid The Sun reported Prince Harry had already left the UK after flying in after the news of Charles' cancer diagnosis was made public.
It was claimed Harry spent 45 minutes with the King in London before flying back to his family in Montecito, California.
The Duke is not believed to have seen his brother William or sister-in-law Kate.
