To this end, CD8+ T cells were isolated from patients (Table S2) with mild COVID-19 (n = 6), severe COVID-19 (n = 6), and healthy controls (n = 3) and enriched for SARS-CoV-2-specific CD8+ T cells by FACS sorting using MHC I Dextramer reagents (Figures 1A, S1A). This evidence concerns the gene CD8A and COVID-19.