Furthermore, mutations in MEFV, NLRP3, NLRP12, NOD2 and LPIN2 have been investigated in genomic DNA samples from patients affected by pyoderma gangrenosum (PG) and its syndromic variants, including also HS in their spectrum, which will be discussed in greater detail later in this review [44]. Here, MEFV is linked to histiocytic sarcoma.