To investigate the notion that infection by Cas9-producing C. jejuni induces cellular stress via p53 after four hours, but not during infection by Cas9-non-producing C. jejuni, gene expression was compared for Caco-2 cells challenged by WT or its isogenic ∆cas9 mutant via the limma t-test (see the methods section). The gene discussed is TP53; the disease is infection.