CD4 and COVID-19: Directly comparing CAP and COVID-19 in an untargeted manner resulted in a modest number (8/86 [9.3%]) of differentially abundant MCs (with BH-adjusted P-values mostly very close to 0.05), including higher frequencies of several CD4, CD8 and TCRγδ T cell MCs (MCs 12, 14, 18, 19, 21, and 24) in COVID-19 and higher frequencies of DCs (MC 66) and non-classical monocytes (MC 73) in CAP (Figure 6B).