As shown in Fig. 1A, 7 FRGs (HSPB1, FANCD2, TFRC, RPL8, CARS, CDKN1A and SLC7A11) were significantly up-regulated in tumor samples, while 8 FRGs, including MT1G, CISD1, FDFT1, SLC1A5, GLS2, ATP5G3, ACSL4 and HSPA5, were found to be significantly down-regulated in ccRCC (Fig. 1B). Here, GLS2 is linked to nonpapillary renal cell carcinoma.