Study participants with HIV/HBV co-infection had low median (IQR) CD4 count compared to HIV mono-infected participants, which was incomparable with what has been reported in previous studies in South Africa (141.6) and Nigeria (121).36 These controversial results may be due either to the difference in the immune status of the participants in these studies or to viral hepatitis co-infection. The gene discussed is CD4; the disease is coinfection.