TNFRSF9 and influenza: The visualization shows that in SARS-CoV-2-stimulated samples, the predominant subpopulations of CD69+CD137+ CD4+ Th cells were represented by CXCR3+CCR4–CXCR5+CCR6– and CXCR3+CCR4+CXCR5+CCR6– cells, whereas in influenza-stimulated samples, the majority of memory Th-lymphocytes consisted of CXCR3–CCR4+CXCR5+CCR6+ and CXCR3–CCR4+CXCR5–CCR6+ subsets.