NEDD4 and neuroblastoma: In summary, our data, for the first time, revealed that exosomal hsa-miR199a-3p could promote tumor proliferation and migration via decreasing NEDD4 expression in NB, suggesting that exosomal hsa-miR199a-3p may be applicated as a fast, easy, and non-invasive detection biomarker and contribute to the development of novel therapeutic strategies for NB in the future.