MAPK1 and nonpapillary renal cell carcinoma: RAP1B (P < 0.001), BRAF (P < 0.05), MEK2 (P < 0.001), ERK1 (P < 0.001), ERK2 (P < 0.01), ETS1 (P < 0.001) and ETS2 (P < 0.001) were enhanced in ccRCC compared with normal renal tissues (Fig. 4).