Adam Yauch aka MCA had been undergoing treatments for cancer since 2009 after a tumor was discovered in his salivary gland, according to Rolling Stone.

Along with working with Beastie Boys comrades Mike “Mike D” Diamond and Adam “Ad-Rock” Horowitz,” Yauch was very involved with the Free Tibet movement and helped with organizing the Tibetan Freedom Concerts during the 1990s.

Yauch’s illness kept him from appearing at the Beastie Boys’ induction into The Rock And Roll Hall Of Fame in April.

Yauch posted a video on the Beastie Boys website in July 2009, according to the New York Daily News, telling fans, “So this is crazy. I have some pretty heavy news … I actually have a form of cancer.”

Funeral arrangements have not yet been announced. Click here for the Beastie Boys website.