EWSR1 and Ewing sarcoma: Most ES cases carry the fusion of the Ewing Sarcoma Breakpoint Region 1 (EWSR1) and FLI1 (Friend leukemia virus integration site 1) genes, leading to an EWS–FLI1 fused protein, which is associated with autophagy, a homeostatic and catabolic mechanism under normal and pathological conditions.