We investigated the significance of the RNA-binding protein IGF2BP3 in the regulation of Ewing sarcoma aggressiveness.<b>Experimental Design:</b> Explorative study was performed in 14 patients with localized Ewing sarcoma using RNA sequencing.
After the formal demonstration of a direct association between IGF2BP3 and <i>IGF1R</i> mRNA using ribo-immunoprecipitation assay, we performed <i>in vitro</i> studies using A673 and TC-71 ES cell lines to demonstrate that IGF2BP3 loss promotes the downregulation of IGF1R and a decreased biological response to IGF1, represented by reduced migration and cell growth.