AceShowbiz - When John Stamos decided to support his old friend and "Full House" co-star Dave Coulier during his fight against cancer, he likely didn't expect backlash. But that's exactly what happened when he donned a bald cap on social media in solidarity with Coulier - prompting Coulier to step in to defend his pal.

Coulier, 65, shared his cancer journey after being diagnosed with stage 3 non-Hodgkin lymphoma. In a heartfelt Instagram post, Coulier expressed his sadness over the negative comments directed at Stamos, who wore a bald cap to support him. Despite the criticism, Coulier emphasized their close friendship and how they are using humor to navigate these difficult times.

"It's our friendship (me and John) and this is how we are handling a very tough time. I'm a comedian and humor is what drives me. John knows how to cheer me up and I laughed out loud when he arrived wearing a bald cap - being a true loving friend and brother," Coulier wrote.

In his controversial post, Stamos wrote a touching tribute to his friend, "You're handling this with so much strength and positivity - it's inspiring. I know you're going to get through this, and I'm proud to stand with you every step of the way. I love you."

Stamos shared three photos on Instagram, wearing a bald cap next to Coulier who had shaved his head, but the post quickly attracted negative remarks. Many followers criticized Stamos for not shaving his head entirely, calling his gesture shallow. One comment read, "Seriously just couldn't shave your head, bro??"

Coulier, however, found Stamos' gesture endearing and humorous. He elaborated on the importance of staying positive and using laughter as a coping mechanism, especially given his family's history with cancer. Coulier has lost his sister, mother, and niece to the disease and knows firsthand the pain and adversity it brings.

"I've heard from so many people who have been inspired enough by my words and actions to say that they are going to check in with their doctors and get mammograms, a colonoscopy or a prostate exam. I'm still going to laugh in the face of adversity," he noted.

Stamos has yet to personally address the backlash, but his wife Caitlin has come to his defense in the comments of Coulier's post. "I really hope the people who chose to say cruel things about my husband - who flew across the country and did what he could do bring joy to his friend going through chemo - look inward," she wrote. "Instead of tearing down others, take that time to think about how you can bring joy to the people you love."

Coulier's wife, Melissa Coulier, also thanked Stamos for his support, further illustrating the tight-knit bond of this extended "Full House" family.

Amid the controversy, Coulier's message is clear: when faced with adversity, the strength in friendship and the healing power of laughter are invaluable. His experience highlights the importance of early cancer detection while shedding light on the profound effects of loyalty and humor.