Val66Met reduces intracellular trafficking and activity-dependent secretion of BDNF.46 Interestingly, meta-analytic evidence suggests lower BDNF levels in people with schizophrenia,47 which may contribute to disease-specific changes of both neuronal synaptic plasticity and the immune system.48 The Val66Met polymorphism may additionally influence food intake and body weight49 in humans. The gene discussed is BDNF; the disease is schizophrenia.