Both World Health Organization (WHO) and South African guidelines for the prevention of MTCT (PMTCT) recommend that all pregnant women be tested for HIV in general antenatal care, and that HIV-infected women start lifelong three-drug antiretroviral therapy (ART) if they require treatment for their own HIV infection based on low CD4 count or WHO Stage 3–4 disease [3–6]. The gene discussed is CD4; the disease is HIV infectious disease.