CCNA2 and infection: Within 5 days of infection with H-RASG12V, both control and ectopic SUV420H2-expressing cells displayed features of cell cycle arrest (decreased expression of cyclin A and PCNA and reduced pRB phosphorylation (based on increased mobility in SDS-PAGE and reduced reactivity with anti-ppRB (Ser780)) and markers of senescence establishment (reduced expression of lamin B1, induction of p16INK4a and p21) (Fig. 6f).