BCL2 and colorectal cancer: The extent to which DAC potentiates CPT-11 or SN-38 might be dependent on the expression level of anti-apoptotic Bcl-2 protein in human colorectal cancer cells, as the higher intracellular protein levels of Bcl-2 were shown to be associated with the resistance of cancer cells to CPT-11 and SN-38 [67–70].