CDKN1A and colorectal cancer: Moreover, a growing body of evidence suggests that p53 regulates ferroptosis either by transcriptional or posttranslational mechanisms such as modulating the downstream expression of SLC7A11,239SAT1 (encoding spermidine/spermine N1-acetyltransferase 1),240GLS2 (encoding glutaminase 2),25 and CDKN1A/p21 (encoding cyclin dependent kinase inhibitor 1A),241 or by directly inhibiting DPP4 activity in colorectal cancer cells.242