WASp-deficient monocytes from patients with classical WAS (Fig. 1a) and WAS KO murine BMDCs (Fig. 1b–e and Supplementary Figs 1 and 2) exhibit increased caspase-1 activity upon NLRP3 activation by ATP and nigericin. Here, NLRP3 is linked to Wiskott-Aldrich syndrome.