CHEK2 and cancer: CCT241533 had a high passive permeability and inhibited Chk2 in cancer cells while showing no effect in combination with DNA-damaging agents, such as SN38, gemcitabine, mitomycin C, bleomycin or etoposide on p53-deficient cells HT29 and HeLa, but interestingly potentiated effect of two PARP inhibitors AG14447 and olaparib [129].