OTUB1 and viral infectious disease: The deubiquitylating enzyme OTUB1 (otubain-1), for example, translocates to the mitochondrion during viral infection to promote the K63 deubiquitylation of TRAF3 and TRAF6 (Li et al, 2010), whereas it simultaneously acts as an inhibitor of the proteasomal elimination of RIG-I (Jahan et al, 2020).