ACE and angiotensin II have been suggested to play important roles in brain dopaminergic neurotransmission [5,6,7]; therefore, the ACE-I/D polymorphism has been investigated in schizophrenia etiology and clinical expression, as assessed using the Positive and Negative Syndrome Scale (PANSS) [4,8,9,10,11,12,13]. The gene discussed is ACE; the disease is schizophrenia.