The multi-cytokine-producing CD4+ T cells are critical for clearing or reducing low levels of viruses in response to infection with various types of viruses, including HIV, influenza virus, Epstein-Barr virus (EBV), varicella-zoster virus (VZV), or cytomegalovirus (CMV), and correlating protection against a second challenge with L. major37. The gene discussed is CD4; the disease is infection.