CDK4 and infection: Among the molecules CDK4, CDK6, and cyclinD (which mediate cell cycle progression in G0/G1; Massagué, 2004) and CDK2 and cyclinE1 (which mediate cell cycle transition from G0/G1 to S phase; Hinds et al., 1992), the expression of CDK6 was not changed, and the expression of cyclinE1 was increased at 24 h post-infecion (Figure 3B), while all of them were significantly decreased in virus-infected cells as compared to mock-infected cells at 28 h post-infection (Figures 3B,G).