PIF1 and nonpapillary renal cell carcinoma: Meanwhile, Figures 4C,D also show that the DSS and PFI in ccRCC patients with a high level of PIF1 were significantly shorter than those in ccRCC patients with a low level of PIF1 (hazard ratio (HR) = 2.58 (1.71–3.88), p < 0.001; HR = 1.49 (1.09–2.04), p = 0.013).