CASP3 and colorectal cancer: Proteasome inhibitors, either as monotherapy or in combination with other agents, have been found to be toxic to colorectal cancer cells, with a number of mechanisms implicated in the mechanism, including suppression of the NF-κB signaling pathway, proteasome-dependent caspase-3 degradation, as well as stabilization of pro-apoptotic Bcl-2 family proteins (9–12).