PTEN and neoplasm: USP7 has a broad range of substrates, such as the tumor suppressors p53 (Li et al., 2002) and PTEN (Phosphatase and tensin homolog) (Song et al., 2008) and the transcription factor FOXO4 (Forkhead box protein O4) (van der Horst et al., 2006), most of which are related to tumor suppression, DNA repair, and immune response (Pozhidaeva and Bezsonova, 2019).