The results of a study by Huang et al. provide new insights into the regulatory role of SUV39H1 in the progression of cancer, and show that SUV39H1 inhibits the transcription of dipeptidyl-peptidase-4 (DPP4) through catalyzing the methylation of DPP4 promoter, therefore reducing the production of lipid ROS and repressing ferroptosis [84, 85]. The gene discussed is DPP4; the disease is cancer.