Reduced IL-17 production may explain the predisposition to epithelial site infections: keratinocytes and bronchial epithelial cells require IL-17A for anti-staphylococcal beta-defensin secretion [41], and epithelial-site staphylococcal infection occurs in other defects disrupting the IL-17 axis including IL-17RA deficiency [42]. The gene discussed is IL17A; the disease is staphylococcal infection.