The majority of DUBs belong to the cysteine protease class, which are further divided into six sub-classes: ubiquitin-specific proteases (USPs), ubiquitin C-terminal hydrolases protease (UCHs), ovarian tumour proteases (OTUs), Machado-Josephin domain proteases (MJDs), the zinc finger with the UFM1-specific peptidase domain protein (ZUFSP/ZUP1) and the motif interacting with the Ub-containing novel DUB family (MINDY) [23,38,39]. The gene discussed is ZUP1; the disease is ovarian neoplasm.