TMCO1 and open-angle glaucoma: Our previous attempts to identify genetic associations between POAG and polymorphisms in genes including caveolin (CAV1/CAV2) [10], atonal homolog 7 (ATOH7) [11], cyclin-dependent kinase inhibitor 2B (CDKN2B) [12], and transmembrane and coiled-coil domain 1(TMCO1) [13] did not yield any positive results indicating that the genetic cause for POAG in patients of Saudi origin may be different than those from European descent.