John Stamos' heartbreaking message to Dave Coulier after his serious cancer diagnosis

After Dave Coulier's cancer diagnosis, the beloved actor has received a host of supportive messages from all his friends, including John Stamos, one of his best friends and one of the people who has always been closest to Coulier, since they were colleagues more than three decades ago on Full House.

The site RadarOnLine.com announced in October that Coulier had been diagnosed with cancer, so Stamos was immediately one of the first to show support for his great friend through his social networks.

Coulier, 65, revealed to the world that he was diagnosed with stage 3 non-Hodgkin's lymphoma, after an upper respiratory tract infection caused severe swelling of the lymph nodes.

John Stamos and Dave Coulier and a friendship over the years

Shortly after Coulier's diagnosis made headlines, Stamos, 61, shared a series of photographs with his Full House co-star, while vowing to support him in his battle with cancer.

The photos showed several moments of closeness and friendship between the two actors from the 90s series, including some images of them making faces during dinner and a mirror selfie that Stamos captured while Coulier was shaving his face.

Stamos captioned the Instagram post: "My brother from day one. I love you @dcoulier and I'll be by your side every step of the way."

This message provoked a wave of positive messages from the two actors' followers.

Fans quickly flooded the comments section of the post with well wishes.

One follower wrote: "These relationships that start at work and end up being friendships for LIFE are extremely rare... and quite beautiful. I love the sisterhood between you!".

Another noted: "He has a great support team and Bob takes care of him! He's got this!" in reference to the couple's late co-star, Bob Saget.

Dave Coulier seeks to be an inspiration to cancer sufferers

Coulier shared the news of her cancer battle in an interview with People the previous month.

He recalled receiving the devastating news after undergoing a series of tests recommended by his doctor: "Three days later, my doctors called me and said: 'We wish we had better news for you, but you have non-Hodgkin's lymphoma and it's called B-cell and it's very aggressive.

"I went from having a little cold to having cancer, and it was pretty overwhelming," he confessed. "This has been a really fast roller coaster ride."

After receiving his diagnosis, Coulier said he called his wife Melissa Bring, as well as friends in the medical field.

"We all put our heads together and said, 'Okay, where are we going?' And they had a very specific plan about how they were going to deal with this," he said.

Two weeks later she began chemotherapy and shaved her head in what she described as a "pre-emptive strike".

In addition, he spoke about the importance of sharing his diagnosis in an episode of his podcast, Full House Rewind, with Marla Sokoloff.

"I started the podcast wearing a hat and said: I've always been a man with many hats, but this hat has a special meaning because a couple of weeks ago I was diagnosed with non-Hodgkin's lymphoma.

"That was really a conscious decision: I'm going to face this head on and I want people to know that it's my life. I'm not going to try to hide anything."

"I'd rather talk about it, open the debate and inspire people," he concluded.