Adam ‘MCA’ Yauch, perhaps best known as a founding member of the Beastie Boys has died at age 47.

The cause of death was not immediately known, although he has been battling with cancer.

Russell Simmons of Def Jam Records said that Yauch “was incredibly sweet and the most sensitive artist, who I loved dearly.” Ben Stiller tweeted that Yauch “stood for integrity as an artist.