MPO and histiocytic sarcoma: The involvement of other autoinflammatory genes, including NOD2, NLRC4 (NLR Family CARD Domain Containing 4), WDR1 (WD Repeat Domain 1), MPO (Myeloperoxidase), and OTULIN (OTU Deubiquitinase With Linear Linkage Specificity), as well as GJB2 (Gap Junction Protein Beta 2), a key gene of keratinization pathway, has been recently found by Marzano et al. In another cohort of syndromic HS patients (4 PASH, 3 PAPASH and 3 PASH/SAPHO), [7] corroborated the polygenic autoinflammatory nature of these HS syndromic forms.