Previously, we reported that IL-17 (A, C, and F), IL-22, and IL-8 mRNAs were upregulated in the lesional skin of PPP patients [32]; confirmed that PPP-VF could upregulate the expression of IL-17C, IL-8, IL-1α, and IL-1β in LSE keratinocytes; and that endogenous hCAP-18/LL-37 induced high-level IL-8 synthesis (Fig. 1). Here, IL17A is linked to palmoplantar pustulosis.