KEAP1 and neoplasm: Heme oxygenase 1 (Hmox1) plays an important role in the growth and spread of tumor, and its expression is regulated positively by Nrf2 [nuclear factor (erythroid-derived 2)-like 2; NFE2L2] and negatively by kelch-like ECH-associated protein 1 (Keap1) and by BTB and CNC homology 1 (Bach1).