At the same time, an analysis of peripheral blood T helper cell differentiation showed that COVID-19 patients had lower proportions of CD4+ T cells with the CD45RA+CD27+CCR7+CD95− phenotype, while the counts of EM2 and EMRA (with CD45RA−CD27−CCR7+ and CD45RA+CD27−CCR7− phenotypes) cells were found to be significantly increased compared to control values [11]. This evidence concerns the gene CD27 and COVID-19.