IL9 and Trichiasis: Curiously, the TNF-308A polymorphism has also been identified [70] as a protective factor in trichiasis (ORA/G = 0.45 [0.25–0.81], P = 0.008∣ORA/A = 0.19 [0.04–1.08], P = 0.062) in a study that also identified homozygosity at a lymphotoxin alpha (LTA) polymorphism (LTA252 ORA/A = 0.25 [0.09–0.63], P = 0.004), heterozygosity at an Interleukin 9 polymorphism (IL9-T113M ORC/T = 0.25 [0.1–0.64], P = 0.004), and heterozygosity at the vascular cell adhesion molecule 1 (VCAM1, OR = 0.47 [0.25–0.86], P = 0.015) as protective factors for trichiasis [70].