A higher caspase-3/7 activation level for mPEO-b-PCCL/SN-38 over mPEO-b-PBCL/SN-38 treatment in some CRC cells could be a reflection of higher micellar kinetic stability of mPEO-b-PBCL/SN-38, which may eventually lead to lower drug release/core cleavage, extracellularly or intracellularly when compared to that for the PCCL/SN-38 based formulation [23]. This evidence concerns the gene CASP3 and colorectal carcinoma.