A substantial body of evidence indicates that CD4+ T cell subsets, including Th1, Th2, Th17, Tfh (T follicular helper, Tfh), Th9, and Treg (regulatory T, Treg) cells, are critically involved in the pathogenesis of liver granuloma formation and fibrosis during schistosomiasis [5,6,7,8]. Here, CD4 is linked to schistosomiasis.