Although activated caspase-1 was shown to be present in both NLRC4 and NLRP3 knockout macrophages eight hours after infection [12], we could not detect any processing of caspases-1, -9, -7 or PARP in macrophages lacking NLRC4 at 1.5 hours post infection, whereas NLRP3-deficient macrophages were still able to cleave caspases and PARP (Figure 5). Here, NLRP3 is linked to infection.