CCR5 and infection: Genes upregulated in the HLA-DR+NKG2C+ samples mostly included those associated with MHC class II and its regulation (alpha and beta chains of HLAs, CIITA), as well as several functional genes: CCR5, a chemokine receptor, is usually upregulated during infection and it is important for NK cell recruitment to inflamed tissue [45]; CD34 is a marker of immature progenitor cells [46]; and STYK1 is serine/threonine/tyrosine kinase 1, which shares its homology with fibroblast growth factor receptors and may regulate cell proliferation and survival [47].