IL1B and Schnyder corneal dystrophy: Since studies on the association of cytokines’ polymorphisms with SCD phenotypes are scanty, the present study aimed to estimate the association of IL-1B+3954 polymorphism with the incidence, clinical and laboratory profiles of Egyptian patients with SCD; and to determine whether IL-1B+3954 polymorphism contributes to the clinical evolution of SCD; and to estimate the value of IL-1B+3954 polymorphism as a genetic predictor of SCD clinical heterogeneity.