Beastie Boys co-founder Adam “MCA” Yauch has passed away.

Although diagnosed with a tumor in his salivary gland back in July 2009, postponing the groups touring plans, it is unclear whether or not his death is related to the cancer he was treated for.

MCA helped form the Beastie Boys back in 1979, alongside pals Mike “Mike D” Diamond and Adam “Ad-Rock” Horowitz.

The legendary group was just inducted into the Rock and Roll Hall of Fame last month, however MCA was unable to attend the ceremony.

The hip-hop icon was 47 and is survived by his wife and daughter.