COPS5 and Machado-Joseph disease: On the basis of our search results, we identified 44 DUBs that were classified into the following DUB subgroups: 23 Ubiquitin specific proteases (USPs), 4 ubiquitin C-terminal hydrolases (UCHs), 1 Machado-Joseph Disease (MJD), 7 ovarian tumour deubiquitinases (OTUs), and 9 JAB1/MPN/Mov34 metalloenzymes (JAMMs) (Table 1).