This approach identified an increase in cells in several clusters, including clusters 1, 2, and 5 in COVID-19 patients, reflecting CD45RA+CD27−CCR7− EMRA-like populations that expressed CX3CR1 and varying levels of T-bet (Fig. 2, I and J) (“EMRA” denotes a subset of effector memory T cells reexpressing CD45RA). The gene discussed is CX3CR1; the disease is COVID-19.