PCNA and Salmonella Infections: Similarly, despite we observed that there were no significant difference in PCNA-positive cells between WT and MLKL−/− mice, MLKL−/− mice presented with notably increased TUNEL-positive cells during Salmonella infection, indicating that activation of the MLKL signal may induce a compensatory tissue homeostatic response in order to preserve the integrity of the epithelial layer during Salmonella infection.