KLF4 and nonpapillary renal cell carcinoma: Table 1 shows the relationship between the KLF4 downregulation in the ccRCC samples and the clinico-pathological parameters of patients with ccRCC. KLF4 downregulation was significantly correlated with tumor stage and tumor diameter (P<0.05). However, no significant correlation was found between KLF4 expressions and age, gender, and Fuhrman grade. These results were further confirmed by western blot. KLF4 expression was lower in 21 of 24 (87.5%) ccRCC samples than in adjacent normal tissues (Figure 1B, C).