The donor 6.5 cells transferred with infection differentiated into IFN-γ-producing Th1 cells, and the donor 6.5 cells transferred 4 days later differentiated into IL-17-producing Th17 cells on day 8 after infection in the lungs of wild-type mice (Fig. 4a–c, Supplementary Note 2, Supplementary Fig. 3). The gene discussed is IL17A; the disease is infection.