NFE2L2 and malignant colon neoplasm: Arlt and colleagues discovered that heightened Nrf2 expression in colon cancer cells and augmented expression of proteasomal subunit proteins S5a/PSMD4 and α-5/PSMA5 increased proteasomal activity provided anti-apoptotic protection and adequate clearance of abnormal proteins in cancer cells and promoted colon carcinogenesis (139).