BDNF and neuroblastoma: The release of neuropeptide Y and neuropeptide Y/neuropeptide Y receptor 5 expression were favored in NB cells after treatment with the brain-derived neurotrophic factor (BDNF); the expression of the BDNF receptor, named tropomyosin-related kinase B receptor, has been associated with a worse prognosis in NB [43,44].