CDKN2A and cancer: In contrast, in the four cancer cell lines (Saos-2, 5637, DLD-1, and HLF), cells infected with Ad-ERE73 (1 + 2)-ARF (−13)-TK and ERE73 (3 + 4)-ARF (−13)-TK demonstrated a significantly higher proportion of cells with subG1 DNA content compared to Ad-pless-TK with increasing MOI (Figure 3A).