One of the main hypothesis is that SIDS is associated with defects in medullary homeostatic control (”brainstem hypothesis”), characterized by malfunctioning neurotransmitter networks, including catecholamines, neuropeptides, serotonin and its receptors, glutamate, brain-derived neurotropic growth factor (BDNF), and some cytokine systems. The gene discussed is BDNF; the disease is sudden infant death syndrome.