TP53 and infection: The Calcein/PI staining assay showed that the proportion of PI+ (dead) cells was significantly lower in H1299-Δ40p53 cell populations than in H1299 cell populations in response to MMS plus rAd-p53 infection, suggesting that Δ40p53 inhibits the function of wtp53 in inducing cell death (Figure 7A, 7C).