OTUB1 and ovarian cancer: OTU domain‐containing ubiquitin aldehyde binding 1 (OTUB1) is a member of the OTU (ovarian tumour) superfamily and has two isoforms.20 The predominantly expressed isoform1 encodes the OTUB1 protein, which functions as a deubiquitinase.21, 22 Researchers have found that OTUB1 fulfils oncogenic functions in somatic malignancies such as breast,23, 24 gastric25 and prostate carcinomas.26 We have also found that OTUB1 promotes tumour progression with an abnormally increased expression in ovarian cancer.25