USP7 and metabolic disease: Accumulating evidence indicates that HAUSP plays critical roles in cancers, neurological disorders, metabolic disorders, immune dysfunction, etc. The first substrate identified for HAUSP-mediated deubiquitination was the tumor suppressor protein TP53 (p53) by Li et al.12 A tumor suppressive role was attributed to HAUSP given its ability to increase the half-life of p53, resulting in growth repression and reactivation of apoptotic pathways.