293 cells were transformed with pCMV or pCMV-DBC2 using Lipofectamine Transfection Reagent (Invitrogen, Carlsbad, CA USA) and harvested with CelLytic MT, 48 hours after transformation. T and E in the figure represent pCMV-DBC2 and pCMV transformants, respectively. Screening of cell cycle regulators. Expression levels of CCNE, CCNB, CCND1, CCNH, p34 and p27 were analyzed with corresponding antibodies: H-145, H-433, M-20, C-18, H-297 and C-19 respectively (Santa Cruz Biotechnology).