(A, B) Western blotting of proteins associated with cell cycle and apoptosis regulation. Western blotting analyses showed that the p53 and p21 levels were upregulated and CDK4, CDK6 and p-Rb (S780) levels were downregulated in shGIMAP2 cells compared with those in shMock cells (*P<0.05, Dunnett's test). Western blotting analyses showed that the Bak and Bax levels were upregulated and the Bcl-2 level was downregulated in shGIMAP2 cells compared with those in shMock cells (*P<0.05, Dunnett's test). Western blotting was conducted three times per cell type. (C) Western blot analysis revealed the p-Rb protein levels and then normalized to total Rb (*P<0.05, Dunnett's test). CDK, cyclin-dependent kinase; sh, short hairpin; GIMAP2, GTPases of immunity-associated proteins 2; p-, phosphorylated.