Previous Nr2f1 conditional mouse models failed in reproducing key patient eye defects, such as malformed optic discs and optic atrophy (Tang et al., 2010), but constitutive models, better mimicking patients’ haploinsufficiency, efficiently recapitulate a plethora of BBSOAS-like symptoms (Bertacchi et al., 2019a). The gene discussed is NR2F1; the disease is Bosch-Boonstra-Schaaf optic atrophy syndrome.