Patient #2 (Responder; resolution of intra-abdominal MAC IRIS lymphadenitis following MAC IRIS therapy and sustained immunologic recovery after the initiation of HAART): A 40-year-old man initially diagnosed with Pneumocystis pneumonia and HIV infection (CD4 cell count 43/mm3, viral load 32,318 c/mL) initially responded well to trimethoprim/sulfamethoxazole and corticosteroids. The gene discussed is CD4; the disease is lymphadenitis.