CD8A and infection: However, in our study, when we compared the polyfunctional activity of CD8+ T-cells in SOTR temporarily controlling the infection in the presence of CD8+ T-cells only (group 3 patients) vs patients developing severe HCMV infection (and even disease) and requiring antiviral treatment (group 4 patients), we did not observe any significant difference in the frequency of multi- vs mono-functional CD8+ T-cells between the two patient groups.