Neurotrophins, including NGF, BDNF, and neurotrophin 3, are increased in asthma and these factors may have important roles in neuroplasticity (Bonini et al., 1996; Virchow et al., 1998; Olgart Hoglund et al., 2002; Watanabe et al., 2015). The gene discussed is BDNF; the disease is asthma.