Certain high penetrance mutations with Mendelian inheritance in myocilin (MYOC), optineurin (OPTN) and cytochrome P450 family 1 subfamily B polypeptide 1 (CYP1B1), and copy number variations of TANK-binding kinase 1 (TBK1) were discovered.[6] Mutations in MYOC and CYP1B1 are causative for HTG, [7, 8] while mutations in OPTN and copy-number variations of TBK1 cause NTG.[4, 5, 9] Despite these successes, highly penetrant Mendelian mutations in genes discovered to date only account for around 5% of all cases of POAG.[6]. The gene discussed is CYP1B1; the disease is open-angle glaucoma.