Interestingly, peroxynitrate is a TrkB receptor agonist that may compete with BDNF for the receptor site, accounting for the elevated BDNF levels documented in patients with chronic PTSD (Yuen et al., 2000; Amoureux et al., 2008; Krolow et al., 2014). The gene discussed is BDNF; the disease is post-traumatic stress disorder.