E2F1 and Salmonella Infections: Conversely, preventing E2F1 downregulation by blocking the activation of the IRE1 pathway (KIRA6 treatment) inhibited Salmonella infection (Fig. 5g, h) and thwarted the increase in Salmonella infection elicited by pre-treatment with the secretome of Salmonella-infected cells (Fig. 5d–f).