NTRK2 and neuroblastoma: Our study provided evidence that BDNF/TrkB increased migration and invasion of TB3 cells through PI3K/Akt and MAPK pathways; together with previous studies that BDNF/TrkB mediated chemo-resistance through PI3K/Akt pathway in the treatment of NB patients [9–14], we believe that BDNF/TrkB and its downstream targets will play very important roles in the treatment of high-risk NB patients, who are suffering from metastasis or/and chemo-resistance.