IL22 and histiocytic sarcoma: To date, thanks to recent studies, we are moving toward the role of cytokines in HS [58,59,60,61]; it has been clarified that there is an overexpression of IL-17A, IL-26, IFN-γ, IL-27, and IL-β and a concomitant downregulation of IL-22 in the lesions of HS patients [59,60].