As NLRC4 lacks the PYD domain, NLRC4 may recruit a PYD-containing protein (such as an NLRP3) to react to bacterial infections.146 Moreover, NLRC4 contains a CARD domain, which suggests direct interactions with procaspase-1.34 ASC is not necessary for NLRC4-dependent caspase-1 activation in response to L. pneumophila. This evidence concerns the gene NLRC4 and bacterial infectious disease.