We also analyzed the methylation of the USP13 promoter in PAAD, HNSC, ccRCC and UCEC, and the results suggested that the USP13 promoter was hypermethylated in PAAD and ccRCC tumor tissues and hypomethylated in HNSC tumor tissues compared with normal tissue samples (Fig. 1K-N). Here, USP13 is linked to nonpapillary renal cell carcinoma.