HIES T cells produce greatly reduced amounts of Th17 cytokines and normal amounts of classical proinflammatory cytokines upon activation. PBMCs from HIES patients (Pt.) and control subjects (Cont.; n = 8 each, indicated by dots) were stimulated (+) or not (−) with anti-CD3 and anti-CD28 for 72 h, and the concentration of the indicated cytokines in their culture supernatants was determined by ELISA. The results shown are representative of three independent experiments. **, P < 0.01.