CD4 and COVID-19: However, we noted a concomitant enrichment of CD3+CD4+ T cells (p = 0.0421, two-tailed Mann–Whitney U-test) and CXCR3+CD11b+CD14+ monocytes (p = 0.0433, two-tailed Mann–Whitney U-test), accompanied by a reduction in natural killer (NK) cells (p = 0.0086, two-tailed Mann–Whitney U-test), and Lin-CD11c-HLA-DR+CD303+CD304+ plasmacytoid dendritic cells (pDCs; p = 0.0022, two-tailed Mann–Whitney U-test) in the COVID-19 patients (Figures 1B–D).