SESN2 and neoplasm: Hemin (Fe3+ heme) induced the expression of sestrin 2 by activating ROS and nuclear factor (erythroid-derived 2)-like 2, and, together with hemin, sestrin 2 overexpression protected colon cancer cells from death including HCT116 and RKO cells and promoted MC38 tumor growth both in vitro and in vivo.