Analysis revealed significantly higher frequencies of activated CD4+ T cells expressing the early activation marker CD69 at 3 dpi (p = 0.01, Fig. 6A,B) and an increased fraction of CD8+ cytotoxic T cells at 3 and 14 dpi (p = 0.06, p = 0.02; Fig. 6C) in the spleens of CLEC12A−/− mice as compared to WT mice upon TMEV infection. The gene discussed is CD69; the disease is infection.