In a model of physiologic low-dose infection with L. major infectious-stage promastigotes (1,000 parasites), mice depleted of all Langerin+ DC developed smaller ear lesions, decreased parasite loads and a reduced number of CD4+Foxp3+ Treg cells, which was accompanied by increased production of interferon γ (IFNγ) (130). The gene discussed is CD4; the disease is infection.