IL6 and sickle cell disease: These observations were corroborated by direct measurements of circulating cytokines, which identified elevation of the proinflammatory cytokines and key drivers of poor outcomes in patients with sickle cell anemia (66) — IL-6, IL-1β, IL-8, and CXCL9 — in recipients of long-stored RBCs, whereas recipients of short-stored RBCs had higher levels of the antiinflammatory cytokines IL-10, IL-12, and CXCL11.