A genetic analysis of auto-inflammation in PG (13 patients) and the syndromic form PASH (7 patients) identified mutations in a range of auto-inflammatory genes (MEFV, NLRP3, NLRP12, NOD2, LPIN2, and PSTPIP1), suggesting the involvement of inflammatory pathways such as NLRP inflammasomes, cystolic pattern recognition sensors, the innate immune system, and IL-1β signaling (33). Here, NOD2 is linked to Pyoderma gangrenosum-acne-suppurative hidradenitis syndrome.