CASP1 and familial Mediterranean fever: While these exo- and endogenous stimuli are not perceived as danger signals or are efficiently suppressed by the normal innate immunity, the facilitated oligomerization of the cryopyrin/NALP3/CIAS1, which is not adequately suppressed by the mutated pyrin in FMF, may be the underlying cause in this disease, resulting in excessive pro-caspase-1 and pro-IL1β processing.