A major region of this tSNE map present in COVID-19 patients, but not HDs or RDs, encompasses CD8 T cells enriched for expression of CD38, HLA-DR, KI67, CD39, and PD-1 (Fig. 2G), highlighting the coexpression of these activation markers with other features, including CD95 (i.e., FAS). Here, ENTPD1 is linked to COVID-19.