Consistent with our present study, previous studies demonstrated that the lower levels of neuropeptide Y in the prefrontal cortex and caudate nucleus of suicide victims [27], and Kang et al. found that hypermethylation of brain-derived neurotrophic factor (BDNF) plays a role in the epigenetic susceptibility of patients with acute coronary syndrome who have a history of suicidal ideation [28]. The gene discussed is BDNF; the disease is acute coronary syndrome.