Mutations involving different autoinflammatory genes (MEFV, NLRP3, NLRP12, NOD2, LPIN2, and PSTPIP1) have been reported in syndromic HS [pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH) syndrome] as well as in pyoderma gangrenosum (PG), a prototypic neutrophilic dermatosis (39). This evidence concerns the gene NOD2 and pyoderma gangrenosum.