CCR7 and COVID-19: In particular, COVID-19 patients were characterized by a decreased percentage of CD45RA−CD27+CCR7− EM1 cells, whereas the proportion of EM2 and EMRA CD3+CD8+ T cells (bearing phenotype CD45RA−CD27−CCR7+ and CD45RA+CD27−CCR7−, respectively) at the onset of SARS-CoV-2 infection was significantly elevated compared with the control group [41].