Among these, mutations in several genes, such as myocilin, optineurin, WDR36 (WD repeat domain 36) and CYP1B1 (cytochrome P450 1B1), are causal or associated with increased risk of developing POAG in multiple populations [7], [8], [9], [10], [11]. Here, CYP1B1 is linked to open-angle glaucoma.