IL1B (interleukin 1 beta) promoter polymorphisms and IL1A (interleukin 1 alpha) intronic polymorphism rs2071376 have been suggested to play roles in KC susceptibility due to significant differences in allelic frequency between groups of KC patients and controls in Han Chinese [91, 119], Korean [120], and Japanese [121] populations. The gene discussed is IL1A; the disease is keratoconus.