FDX1 and nonpapillary renal cell carcinoma: Through univariate and multivariate regression analysis, we found FDX1 expression level could function as an independent factor for the OS (univariable: HR 0.77 (0.67–0.88, p < 0.001); multivariable: HR 0.87 (0.77–0.98, p = 0.025)) and PFS (univariable: HR0.76 (0.67–0.88, p < 0.001); multivariable: HR0.87 (0.77–0.98, p = 0.022)) of ccRCC (Table S1).