In an Icelandic genome-wide association study of POAG, gene variants in the intergenic region between caveolin 1 and caveolin 2, which code for caveolins that reside near NOS3 in endothelial cell membranes and serve to mediate endothelial tone were associated with POAG [39]. The gene discussed is CAV1; the disease is open-angle glaucoma.