DPP4 and nonpapillary renal cell carcinoma: Consequently, distinct expression levels of ferroptosis regulators were found in ccRCC and normal tissues (Figures 1A,B), including upregulated ferroptosis regulators CDKN1A, HSPA5, EMC2, SLC7A11, MT1G, HSPB1, FANCD2, SLC1A5, RPL8, LPCAT3, DPP4, and CARS (p < 0.05) and downregulated regulators NFE2L2, GPX4, CISD1, FDFT1, NCOA4, GLS2, CS, ATP5MC3, and ACSL4 (p < 0.05).