NTRK2 and neuroblastoma: Increased TrkB protein expression was recently observed in breast cancer specimens compared with normal breast tissue [26], [33], and although a correlation with clinical outcomes was not assessed in these studies, elevated TrkB expression in neuroblastoma is correlated with a chemo-resistant phenotype [40], with increased mortality in Wilm's tumor [41] and is a predictor of distant metastases and prognosis in gastric cancer [42].