Although expression of CD107 and IFNγ production by intraepithelial and splenic γδ T cells, cytotoxic CD8+ T cells, and splenic helper CD4+ T cells did not significantly differ between uninfected and SE-infected chickens, proliferation of SE-induced splenic T cells of SE-infected chickens ex vivo was observed 3 weeks after infection and not in uninfected chickens. The gene discussed is IFNG; the disease is infection.