A large set of scientific reports has been issued demonstrating that PACAP exerted neuroprotective effects in retinal disorders such as diabetic retinopathy, UV-A triggered apoptosis, ischemia, optic neuritis, traumatic optic neuropathy, and glaucoma due to its anti-apoptotic and/or anti-inflammatory action [23–28]. The gene discussed is ADCYAP1; the disease is diabetic retinopathy.