BDNF and neuroblastoma: In the brain, hypoxia increases BDNF expression,[28,29] and BDNF may modulate neuronal cell survival.[30] Similarly, BDNF has been shown to play a role in cardiac myocyte survival following infarction.[31] Furthermore, in neuroblastoma cell lines[32] as well as rat airway cell lines,[33] TrkB expression is mediated, in part, by exposure to low oxygen tensions.