In particular, in recent years, somatostatin (somatotropin release inhibiting factor, SRIF) and pituitary adenylate cyclase activating peptide (PACAP) have been reported to be highly protective against retinal cell death caused by ischemia, while data on opioid peptides, angiotensin II, and other peptides have also been published. This evidence concerns the gene ADCYAP1 and ischemia.