Kling et al. demonstrated that hypoxia induced tumor derived exosomal miR-210 targets the proapoptotic protein caspase-8-associated protein 2 (CASP8AP2) in recipient cells, whose suppression led to a decrease in apoptotic cells and promoted sphere formation by regulating Ewing’s sarcoma stem-like cells [39]. This evidence concerns the gene CASP8AP2 and Ewing sarcoma.