In brief, the scRNA-seq followed by the immune transcriptomic analysis indicated an activation state (through CD69 and HLA class II genes), chemotaxis (e.g., CCL3 and CCL4), an inflammatory state (e.g., NFKBIA, PIK3R1, S100A9, etc.)in T cells, especially in CD8+T cells, in COVID-19 cases. The gene discussed is CD8A; the disease is COVID-19.