F5446 (Compound 1) is a selective small molecule inhibitor of SUV39H1 methyltransferase. F5446 decreases H3K9me3 deposition at the FAS promoter, increases Fas expression and increases colorectal carcinoma cell sensitivity to FasL-induced apoptosis in vitro. F5446 suppresses human colon tumor xenograft growth in vivo[1][2][3].