When evaluating the potential pathophysiological role of vasoactive endogenous neuropeptides in sSAH-related cerebral hemodynamic changes, CV-induced cerebral ischemia, and outcome after sSAH, neuropeptide Y (NPY) [24–27] and calcitonin gene-related peptide (CGRP) [28–33] have gained paramount interest. The gene discussed is CALCA; the disease is Cerebral ischemia.