The observation that both antigen-specific and antigen-unrelated CD8 T cells cluster around infected hepatocytes led to the proposal that antigen-specific effector CD8 T cells recruit other T cells to the site of infection and that the resulting inflammatory microenvironment augments parasite killing by antigen-specific and antigen-unrelated bystander cells (Bayarsaikhan et al., 2015). The gene discussed is CD8A; the disease is infection.