After exclusion of patients lost to follow-up and not evaluated, death in TB/HIV co-infected patients during TB treatment was associated with a TB diagnosis made before 2010 (aOR = 2.50 [1.31–4.78]; p = 0.006), the presence of other AIDS-defining diseases (aOR = 2.73 [1.27–5.86]; p = 0.010), non-AIDS comorbidities (aOR = 3.35 [1.37–8.21]; p = 0.008), not receiving cotrimoxazole prophylaxis (aOR = 3.61 [1.71–7.63]; p = 0.001), not receiving antiretroviral therapy (aOR = 2.45 [1.18–5.08]; p = 0.016), and CD4 cells count <50 cells/mm3 (aOR = 16.43 [1.05–258.04]; p = 0.047). The gene discussed is CD4; the disease is tuberculosis.