RAC2 was up-regulated in RCC cells and tissues. (A and B) Reverse transcription-quantitative PCR assays of RAC2 mRNA expression in normal renal tubular epithelial cells (HK-2) and renal cancer cell lines (A498, ACHN, CAKI-1, OSRC-2, 786-O), and in 50 paired tissue samples of patients with ccRCC. (C and D) Western blot assays of RAC2 expression in normal renal tubular epithelial cells (HK-2) and in renal cancer cell lines (A498, ACHN, CAKI-1, OSRC-2, 786-O) and in 50 paired tissue samples of ccRCC patients. (E) Immunohistochemistry for RAC2 expression in ccRCC tissues, adjacent normal tissues and renal angiomyolipoma tissues. The inset images are the lower magnification of the same tissue as that presented in the larger image of each set. Magnification, ×40 and ×200. RAC2 expression was normalized to β-actin expression. The values of each group are presented as the mean ± standard deviation. Bars represented the means of three independent experiments. ****P<0.0001; **P<0.01 vs. HK-2. RAC2, Rac family small GTPase 2; ccRCC, clear cell renal cell carcinoma.