IDO1 and nonpapillary renal cell carcinoma: The LASSO logistics regression and SVM-RFE algorithms (Figures 4(a), 4(b), and 4(c)) revealed that 19 rejection-related genes involved in ccRCC occurrence, including RAC2, PLA1A, NLRC5, LAPTM5, TYROBP, TAP1, CCL8, IRF1, GBP2, PSMB9, FCN1, GBP1, GPR171, ITK, PLAC8, CCL5, ADAMDEC1, IDO1, and CXCL9 (Figures 4(d) and 4(e)).