CD8A and hemophagocytic syndrome: Activated DCs promote T cell, particularly CD8+ T cell, proliferation and production of IFN-γ and IL-17A.22 Intriguingly, a secondary hemophagocytic lymphohistiocytosis, which associates with a massive CD8+ T cell and macrophage activation but decreased NK cell activity, has been noted for COVID-19 patients in European ICUs.