ACVRL1 and colorectal carcinoma: To further identify whether ACVRL1 stabilizes GPX2 through the deubiquitination mediated by USP15, we overexpressed both USP15 and HA-UB in CRC cells and then treated the cells with proteasome inhibitor MG132, the results showed USP15 overexpression significantly inhibited the ubiquitination of GPX2, which could be rescued by the depletion of ACVRL1 (Fig. 4I).