Identify and design therapeutically relevant miRNA mimic or trap payloads to enhance chemotherapy sensitivity in Ewing Sarcoma cells. Combination of bioinformatic tools and in vitro assays will be used to refine 63 previously identified miRNAs and isolate specific miRNAs which may impact chemosensitivity within a panel of 8 Ewing Sarcoma cell lines. Engineer exosomes to deliver therapeutically relevant miRNA mimic or trap payloads to EWS cells and tumors.