The identification of OPA1 mutations as causative for selective neurodegeneration of retinal ganglion cells (RGCs) leading to optic atrophy was thus instrumental in opening a very active field of investigation for neurology and neuro-ophthalmology as well as in understanding new mechanistic pathways regulating mitochondria homeostasis and primarily mitochondrial dynamics (23). The gene discussed is OPA1; the disease is optic atrophy.