RCC2 knockdown suppresses cell proliferation. MKN45 cells were transfected with siRNA against RCC2, PPIC or a negative control. The downregulation of RCC2 protein and PPIC mRNA was confirmed (A). Cell viability at 72 h (B), BrdU incorporation at 24 h (C) and caspase-3/7 activities at 72 h (D) were determined. These data are shown as mean ± SD of quadruplicate determinations. *P <0.05. **P <0.01.