Although previous studies, in different models of infection, have shown the importance of MyD88 signaling intrinsic to T cells, none of those works has identified the receptor upstream the MyD88 adaptor molecule playing a determinant role for the Th1 response in vivo (Frazer et al., 2013; LaRosa et al., 2008; Raetz et al., 2013; Zhou et al., 2009). The gene discussed is MYD88; the disease is infection.