NOS3 and isolated cleft palate: Penile erectile failure in CPI was associated with upregulation of cytokines, loss of neural structural integrity, and impairment of nitric oxide (NO ̇)-cyclic guanosine 3’, 5’-monophosphate (cGMP) signaling pathway due to lack of neuronal and endothelial nitric oxide synthase in the ischemic erectile tissue [20,21].