TP53 and infection: Oliver Terrier et al. have shown that during infection of A549 cells with diverse influenza A virus subtypes (H3N2, H5N1, H5N2, or H7N1), there were global down-regulation of genes both upstream and downstream of p53, such as AKT1, PTEN, p21, PERP, FAS, DR4/5, BAX, Bcl-XL, PAI-I, and so on, attenuating the entire p53 cascade [105].