B3GAT1 and COVID-19: Using CD28, KLRG1, CD57, TIGIT, PD‐1, and ICOS as biomarkers, higher frequencies of CD8+ and CD4+ T cells with mixed senescence/exhaustion phenotypes were observed in individuals with severe COVID‐19 when compared to individuals with mild disease and, for specific phenotypes, to individuals with moderate disease (Figure 3).