Fig. 1

A Representative immunohistochemical staining of IDH1 in ccRCC tissues. A (a). Negative staining of IDH1 in ccRCC, score 0. A (b). Weak staining of IDH1 in ccRCC, score 3. A (c). Moderate staining of IDH1 in ccRCC, score 6. A (d). Strong staining of IDH1 in ccRCC, score 12. Bar: 100 μm. B Frequency distribution of tumoral IDH1 immunohistochemistry integrated comprehensive score in 358 ccRCC samples. C Comprehensive score of IDH1 expression level in tumor and peritumor tissues. p value < 0.05 was regarded as statistically significant