The induction of mouse NLRP3 mutants (R258W, D301N and Y570C), corresponding to the major human CAPS-associated-mutations (R260W, D303N and Y570C, respectively),19 by the Tet-on system in the presence of pro-IL-1β resulted in the release of mature IL-1β (Figure 2a and Supplementary Figure S2b) and caspase-1 activation (Figure 2b) even without a second signal after doxycycline treatment. The gene discussed is CASP1; the disease is cryopyrin-associated periodic syndrome.