NTRK1 and melanoma: Peinado and colleagues have recently shown that cancer-derived exosomes modulate the crosstalk between malignant cells and the bone marrow microenvironment; they reported, for the first time, that metastatic melanoma cells release exosomes that are able to “educate” bone marrow progenitors thereby inducing their mobilization which supports tumor vasculogenesis, invasion and metastasis, through the activation of the MET receptor tyrosine kinase.