Binds to and inhibits caspase-9, caspase-8 and caspase-4. therefore preventing caspase-induced apoptosis in the host cell [1].

1: The E. coli effector protein NleF is a caspase inhibitor. Blasche S, Mortl M, Steuber H, Siszler G, Nisa S, Schwarz F, Lavrik I, Gronewold TM, Maskos K, Donnenberg MS, Ullmann D, Uetz P, Kogl M; PLoS One. 2013;8:e58937. PMID:23516580