(From left) John Stamos and Dave Coulier on 'Who Wants to be a Millionaire' in July.
CNN  — 

As Dave Coulier continues to go through cancer treatment, he is getting some support from his friend John Stamos.

Coulier debuted his newly shaved head in a photo posted to his “Fuller House” co-star’s Instagram page on Monday, five days after he publicly shared that he was recently diagnosed with stage 3 non-Hodgkin lymphoma, a blood cancer.

In one photo, Coulier and Stamos are smiling while both sporting shaved heads – with Stamos clarifying in the caption that he wore a bald cap for the occasion “to show some love and solidarity with my bro.”

Stamos is seen holding the shaver to Coulier’s head as he helps him buzz his hair in the next photo. In a third photo, Stamos and Coulier’s wife Melissa Coulier are seen kissing his head.

“You’re handling this with so much strength and positivity— it’s inspiring,” Stamos wrote in the caption. “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.”

On Tuesday, Coulier defended his friend’s choice to wear the bald cap, responding to what he described as “negative comments.”

“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 on his Instagram page.

He said laughter and positivity helped him get through losing several family members to cancer and “I’m still going to laugh in the face of adversity.”

“I’m choosing to spread the word about early cancer detection to help people. That’s just who l am,” Coulier wrote. “I wish nothing but love for all of you.”

Coulier, who is best known for playing Uncle Joey on the ‘90s family sitcom “Full House” and the 2016 reboot “Fuller House,” first shared his cancer diagnosis publicly last week. He was diagnosed about five weeks ago.

“In that time I’ve had three surgeries, I’ve had chemo, I’ve lost a little bit of hair,” he said, patting his head in an interview with NBC. “It has been a rollercoaster ride, for sure.”

Coulier said at the time he’d already given himself a buzz cut, describing as a “preemptive strike” because he knew that hair loss was “coming” as he continues his treatment.

He went on to joke that with less hair, his hockey helmet fits better.

“I’m more aerodynamic on the ice,” he said, with a laugh.