The most common predictors are age [7, 10–14], gender [10–12], being orphan [15], time from ART initiation [15], poor adherence to ART failure [10, 11, 16–18] [19], nevirapine (NVP)-based regimen [13, 20], drug side-effects, drug toxicity [10, 11, 16, 17], nutritional status [11], pretreatment CD4 count [1, 10, 11, 13, 14, 16, 19, 21], WHO clinical stage [9–11, 16, 19, 21] and tuberculosis co-infection [9, 19]. The gene discussed is CD4; the disease is tuberculosis.