JOSD2 (Josephin-2) is a member of the Machado-Joseph Domain (MJD) deubiquitinating enzyme family. Other family members include: Ataxin-3, Ataxin-3L, and JOSD1. JOSD2 preferentially cleaves K63-linked ubiquitin chains, with much weaker activity toward K48-linked ubiquitin chains in vitro.