CD2 and colorectal carcinoma: Specifically, the exon 4B isoform of ZIP14 is found to have an eightfold higher affinity for Cd2+ than the exon 4 A isoform, which is known as a potent carcinogen.99 Moreover, Cd2+ has been found to influence several cellular processes, including apoptosis, differentiation, and cell growth, especially the inhibition of DNA mismatch repair,418,419 thus setting off CRC carcinogenesis.