CD8A and infection: Lymphocytes expressing the NKG2D receptor are present in the eye during episodes of inflammation [58,70], and there is evidence that both NK and CD8+ T cells are important components of the immune response against T. gondii. It is known that the expression of MICA molecules increases in response to infections and can trigger cytotoxicity and IFN-γ secretion by cells expressing the NKG2D receptor [71].