The BAP1 inhibitor TG2-179-1, which inhibits the DUB activity of BAP1 possibly by binding covalently to the active site, exhibits potent cytotoxic activity against colon cancer cells, with IC50 values of less than 10 μM, and inhibits the growth of colon tumors in xenograft mice. This evidence concerns the gene BAP1 and malignant colon neoplasm.