NTN1 and diabetic retinopathy: For instance, semaphorin 3A (Sema 3A) increases in the retina after retinal detachment,57,58 optic nerve axotomy,59 diabetic retinopathy,60 OIR,61 and glaucoma;62 netrin-1 is upregulated in OIR and diabetic retinopathy;63–66 eph/ephrin signaling is involved in OIR and diabetic retinopathy67–69 and increases in glaucoma.70