While PKCδ and NLRC4 co-immunoprecipitated with each other in response to infection as expected, neither protein co-immunoprecipitated with CrkI or CrkII isoforms of Crk (Fig. 6a and Supplementary Fig. 6a), suggesting that Crk functions upstream of PKCδ phosphorylation. The gene discussed is NLRC4; the disease is infection.