Although reconstitution of the host immune system via highly active antiretroviral therapy (HAART) in AIDS-KS or change of immunosuppressive regimens in iatrogenic KS often leads to clinical regression of KS (6), an improper immune response in immune reconstitution inflammatory syndrome (IRIS) during HAART-initiated repopulation of CD4+ T cells can lead to KS lesion progression (6). The gene discussed is CD4; the disease is Kaposi's sarcoma.