IL6 and Schnyder corneal dystrophy: Plausible mechanisms include hydroxyurea's effect on reducing pro‐inflammatory cytokines inclusive of interleukin‐6 (IL‐6), IL‐8 and tumor necrosis factor‐alpha (TNF‐α) and beneficial effect on the microvascular circulation though increasing nitric oxide donation and intracellular signaling in SCD [40, 41].