In COVID-19 patients, the TM, EM, and EMRA CD8+ T cell subsets showed a higher frequency of CD226 compared to healthy controls, while in malaria patients the upregulation of CD226 was significant across all differentiation subsets compared to healthy individuals which implies a highly activated and functional phenotype of these cells (Figure 2B and Supplementary Figure 4A). The gene discussed is CD8A; the disease is COVID-19.