CTLA4 and nonpapillary renal cell carcinoma: The actual expression levels of common ICI genes (KDR, KIT, and VEGFR), angiogenesis-related genes (PD-1, PD-L1, and CTLA4), and prognostic-related MTGs (ACAD11, ACADSB, BID, PYCR1, SLC25A27, and STAR) in ccRCC and normal renal tissues were detected by RT-qPCR to further evaluate the reliability of the prognostic signature.