The chronic phase of infection or clinical latency (1 to 20 years after acute infection) is characterized as an asymptomatic phase with a continued decline of CD4+ T cells, usually correlating with AIDS progression along with the level of immune activation, presenting with constant or slow levels of viremia (in the order of 1 to 100,000 copies/mL) [33,34]. The gene discussed is CD4; the disease is AIDS.