Cells were infected with either Ad·(ST13)·CEA·E1A(Δ24), Ad·(EGFP)·CEA·E1A(Δ24) or ONYX-015 at an MOI of 10 for different lengths of time (24, 48, 72, or 96 h), and the cell viability after infection was determined using the MTT assay. This evidence concerns the gene CEACAM5 and infection.