CD8A and hemophagocytic syndrome: The pathogenesis of HLH involves the dysfunction of natural killer (NK) cells and cytotoxic T cells leading to prolonged and intense activation of antigen-processing cells (macrophages and histiocytes) [28] and CD8+ T cells, and excessive proliferation and ectopic migration of T cells, which triggers overproduction of proinflammatory cytokines, and unrestrained hemophagocytosis [29].