It is possible that this transition reflects the inability of CD4+TNF-α-producing T cells to eradicate the infection alone, which seems to be supported by the finding that the majority of TNF-α-producing CD4+ T cells before treatment did not co-produce IFN-γ or IL-2, whereas at follow-up, the majority of IFN-γ-producing CD4+ T cells co-produced either TNF-α or IL-2, a phenotype highly indicative of functionally superior cells (23). Here, CD4 is linked to infection.