CD8A and COVID-19: A recent scRNA-seq analysis of virus-reactive CD8+ T cells obtained using ARTE demonstrated that the proportion of the “exhaustion” CD8+ T-cell cluster characterized by increased expression of exhaustion-associated genes, including HAVCR2 (TIM-3) and LAG3, was higher in SARS-CoV-2-reactive CD8+ T cells from COVID-19 patients than in influenza A virus (IAV)- and respiratory syncytial virus (RSV)-reactive CD8+ T cells from healthy donors [111].