USP7 and cancer: USP7 is a ubiquitin- hydrolysing enzyme that is profoundly implicated in the diverse malignant phenotypes of cancers as it targets multiple substrates, such as TP53,26 N-MYC,27 Gli128 and Yap.29 Recently, two reports have well documented how USP7 regulates β-Catenin ubiquitination and affects its stabilisation.