Our data also showed higher CCR5 co-expression on CD4 + cells in the epithelium of both outer (median of 97%) and inner tissue (median of 98%) compared with the sub-stratum outer (median of 86%) and inner (89%) tissue (Fig. 3a; q < 0.0001), and appeared to be unrelated to STI status. This evidence concerns the gene CD4 and sexually transmitted disease.