The recent meta-analysis of Mojtabavi and coauthors [57], reporting an increased plasma BDNF in PTSD patients, points out some of these aspects while encouraging the pursuit of investigations on BDNF and PTSD considering a wider cohort of patients to permit their distinction with respect to the chronological distance from the traumatic event and the kind of experienced traumatism. The gene discussed is BDNF; the disease is post-traumatic stress disorder.