IL37 and acquired polycythemia vera: However, despite the significant overlapping immune functions of IL-36 and IL-17 cytokines in the skin, the predominant role of IL-36 signaling in GPP is underscored by the variable and inconsistent clinical efficacy of off-label IL-17 antagonists for the treatment of GPP; in contrast, most patients with PV have consistent clinical responses to selective IL-17 and IL-23 inhibitors.