To investigate a functional correlate of the early increased footpad swelling of the T cell-specific and the complete IL-10-deficient mice, we restimulated lymph node cells of the different IL-10-deficient mouse strains with L. major lysate 7 days after infection and assayed for the production of IFN-γ, IL-4, IL-10 and IL-17. The gene discussed is IL17A; the disease is infection.