Although previous studies had shown the importance of IL-23 in mediating the development of pathogenic CD4+ T-cell population that produces differential IL-17 (a cytokine associated with higher pathology in schistosomiasis), we found no association between the risk of schistosomiasis-associated IRIS and magnitude of change in CD4+ cell counts or decrease in HIV viral load. The gene discussed is CD4; the disease is schistosomiasis.