The FPTOS_score of each ccRCC patient was computed applying the following formula: FPTOS_score = (-0.2832 × Exp ACADSB) + (0.2549 × Exp CDCA3) + (0.1523 × Exp CHAC1) + (-0.1508 × Exp MYCN) + (0.0672 × Exp TFAP2A). This evidence concerns the gene CHAC1 and nonpapillary renal cell carcinoma.