Several types of immune cells and their products function to contain and clear HSV infections such as keratinocytes, which produce chemokines that recruit T cells to the site of infection (5), infiltrating CD4 T cells which secrete interferon-γ (IFN-γ) (6) and effector CD8 T cells that clear infected lesions via direct killing or IFN-γ control of HSV-infected cells (7). The gene discussed is IFNG; the disease is infection.