Given the integral role of epigenetic deregulation in Ewing sarcoma pathogenesis, and our observations that the transition of CXCR4 negative cells into CXCR4 positive states is associated with changes in levels of CXCR4 transcript, we investigated whether epigenetic plasticity contributes to stress-induced plasticity. Here, CXCR4 is linked to Ewing sarcoma.