It has been previously demonstrated that NLRC4/NAIP5-mediated caspase-1 and caspase-7 activation regulates host cell death by both pyroptosis and autophagy means and facilitates bacterial degradation by stimulating the fusion of Legionella-containing phagosomes and lysosomes within 2 h after infection [197,227,228]. Here, CASP1 is linked to infection.