A protective role for IL-17 in TB has been reported in mice34,35 and more recently in rhesus macaques.29 The frequency of IL-17-producing CD4 T cells in the BAL was low after ID BCG immunization, and was not increased by boosting with either Ad5(TB) or protein plus adjuvant boosting (Supplementary Fig. 3a). The gene discussed is CD4; the disease is tuberculosis.