IL1RL2 and histiocytic sarcoma: This latter finding, together with the increased expression of IL-36 cytokines in lesional HS skin, led the researchers to hypothesize the existence of an autocrine loop in HS, maintained by the simultaneous secretion of IL-36 and the expression of IL-36 receptors (IL-36R) by both keratinocytes and dendritic cells (a major source of proinflammatory cytokines) [121].