TET1 and nonpapillary renal cell carcinoma: Furthermore, we discovered a favorable correlation between the expression of several DNA methylation-related enzymes and the expression of the CASZ1 gene in ccRCC, including TET2 (r=0.439, P<0.001), TET3 (r=0.29, P<0.001) and TET1 (r=0.182, P<0.001) (Fig. 2B).