DPP4 and colorectal cancer: For example, in colorectal cancer, p53 antagonizes erastin-induced ferroptosis by limiting dipeptidyl-peptidase-4 (DPP4) activity and reducing DPP4-dependent lipid peroxidation (Xie et al., 2017); activation of p21 downstream of p53 delays the onset of ferroptosis, partly due to conservation of intracellular GSH upon cell cycle arrest (Tarangelo et al., 2018; Venkatesh et al., 2020).