We then focused on the AXL, a key player in regulating the sunitinib resistance [13, 16], and results revealed that increasing the TR4 expression with TR4-cDNA or suppressing TR4 with TR4-shRNA altered the AXL mRNA expression in both RCC OSRC-2 and SW839 cells (Fig. 2a, b). The gene discussed is AXL; the disease is renal cell carcinoma.