FLI1 and neuroblastoma: To determine whether the level of miR-210-3p in EVs released by NB cells affects cells migration and invasion in vivo, we established a xenograft model [53] using two zebrafish (Danio rerio) strains: the Casper strain lacking all melanocytes and iridophores [28] and the transgenic zebrafish line Tg(fli1:EGFP) expressing enhanced GFP in the vasculature [54].