Genetic linkage studies have so for identified more than 20 gene loci that contribute to the genetic risk of POAG, such as myocilin (MYOC), optineurin (OPTN), caveolins 1 and 2 (CAV1/CAV2), cyclin-dependent kinase inhibitor 2B antisense (CDKN2B), and growth arrest-specific 7 (GAS7) [4, 25]. This evidence concerns the gene CDKN2B and open-angle glaucoma.