However, STI was associated with a significant reduction in breadth of bifunctional CD8+IFNγ−Perforin+ responses (median −1, IQR 0 to −3.3 protein pools) compared to CT, (median 0, IQR −2.0 to 3.0 HIV protein pools) (Figure 4(c)). This evidence concerns the gene CD8A and sexually transmitted disease.