Using these two parameters, a differentiation block from effector memory cells (CCR7−/CCD45RA−) to terminally differentiated effector cells (CCR7−/CD45RA+) has been reported in chronic progressive HIV-1 infection, resulting in a relative paucity of fully mature virus-specific effector CD8+ T cells [20], [27]. The gene discussed is CD8A; the disease is HIV-1 infection.