USP4 and neoplasm: USP4 inhibits p53- and p53-mediated apoptosis, regulates NF-κB signaling pathway and modulates TGFβ signaling,60, 82, 83, 84 promoting breast cancer85 and lung adenocarcinoma invasiveness.86 We demonstrate here that both USP17 and USP4 are expressed at higher levels in breast and lung cancer cell lines compared to normal cells.