PCR assay confirmed COVID-19. Lung biopsy showed bilateral diffuse alveolar damage with exudates, b/l lung showed evident ARDS. Biopsy of heart tissue showed no substantial damage. Liver biopsy showed injury caused by SARS-CoV-2 infection or drug toxicity. Flow cytometry showed an increase of Th17 and high cytotoxicity of CD8 T cells. Lymphopenia with reduced peripheral CD4 and CD8 T cells, elevated AST/ALT ratio and elevated LDH, hypoalbuminemia, elevated IL-6 and CRP. This evidence concerns the gene CD8A and COVID-19.