Tyler died "peacefully in his home" on Sunday, according to a statement from his longtime manager Toni Benson. The actor starred in 150 "Friends" episodes as Gunther, who carried an unrequited love for Rachel (Jennifer Aniston).
"The world knew him as Gunther (the seventh 'Friend') but Michael’s loved ones knew him as an actor, musician, cancer-awareness advocate, and loving husband," the statement said.
Aniston paid tribute with an Instagram post Sunday featuring a video of that "Friends" episode where Rachel kissed the ever-adoring Gunther on the cheek.
"Friends would not have been the same without you," Aniston wrote with a broken heart emoji. "Thank you for the laughter you brought to the show and to all of our lives. You will be so missed."
Other "Friends" stars weighed inCourteney Cox wrote on Instagram, "The size of gratitude you brought into the room and showed every day on set is the size of gratitude I hold for having known you. Rest in peace James."
Matt LeBlanc displayed a photo on Instagram of his "Friends" character Joey with Gunther on the set. "We had a lot of laughs buddy. You will be missed. RIP my friend."
Lisa Kudrow and David Schwimmer also paid tribute. "Thank you for playing such a wonderful, unforgettable role in Friends and for being such a big hearted gentleman and all around mensch off screen," Schwimmer wrote.
"Friends" co-creator Jeffrey Klarik tweeted Sunday that Tyler "was a lovely, lovely man. Today is a very sad day."
In June, the actor revealed he was undergoing chemotherapy treatment after being diagnosed with Stage 4 prostate cancer.
"I'm sorry to say that I'm not appearing today with you to announce that there's a 'Friends' movie," Tyler told the "Today" show. "Actually, I'm here to let you know that in September of 2018, I was diagnosed with advanced prostate cancer."
James Michael Tyler: Gunther on 'Friends,' reveals Stage 4 prostate cancer diagnosis
Tyler had hoped to attend the HBO Max "Friends" reunion in May, but said he withdrew from appearing because of his health.
"I wanted to be a part of that, and initially I was going to be on the stage," Tyler explained. "It was my decision not to be a part of that physically and make an appearance on Zoom, basically, because I didn't wanna bring a downer on it. I didn't want to be like, 'Oh, and by the way, Gunther has cancer.' "
Tyler's doctors discovered his cancer during a routine physical, in which he took his first prostate specific antigen (PSA) test. Though his early prognosis was "optimistic," Tyler said the cancer mutated during the pandemic, spreading to his bones and spine, resulting in his inability to walk.
"It's Stage 4, late stage cancer, so eventually, it's gonna probably get me," Tyler told "Today." While he expressed regret for not getting tested sooner, Tyler became an advocate for early testing.
Actor James Michael Tyler (@slate_michael) played Gunther on “Friends” for 10 years, but he was unable to attend the recent cast reunion in person because he’s been battling a serious health issue. Now he’s sharing his news for the first time with @craigmelvin. pic.twitter.com/272tg4Sbvc
— TODAY (@TODAYshow) June 21, 2021
"My goal this past year was to see my 59th birthday. I did that," he said. "My goal now is to help save at least one life by coming out with this news."
The Clemson University graduate had worked as a barista at Los Angeles' Bourgeois Pig coffee shop. The aspiring actor made appearances on "Sabrina the Teenage Witch" and "Just Shoot Me!" before landing the career-changing "Friends" role.
Co-creators Marta Kauffman and David Crane credited Tyler for the character's evolution in a statement Sunday to USA TODAY: "James was a genuinely kind, sweet man. When he started as an extra on 'Friends,' his unique spirit caught our eye and we knew we had to make him a character. He made Gunther's unrequited love incredibly relatable."
While undergoing treatment, Tyler starred in two short films: "The Gesture and the Word" and "Processing."
"Even three days ago, he said to me how proud he was to win awards for his short films," Benson said.
In 2021, Tyler's spoken word performance of Stephen Kalinich’s poem "If You Knew" was adapted into a short video to raise awareness for the Prostate Cancer Foundation.
Tyler is survived by his wife, Jennifer Carno, who was described in the statement as the "the love of his life, ever united in good times, in sickness, and for eternity."
Contributing: Jenna Ryu
This article originally appeared on USA TODAY: James Michael Tyler dies: Jen Aniston leads 'Friends' tribute to Gunther