Our cellular study showed that upon knockdown of HHLA2 expression in human ccRCC cell lines, the cell viability, the migration and the invasion ability were significantly inhibited, while the cell cycle arrest at G1 phase was induced and the expressions of Cyclin D1, c-Myc and Cyclin E1 were decreased. This evidence concerns the gene CCNE1 and nonpapillary renal cell carcinoma.