EWSR1 and neoplasm: However, whether the hypoxic gene signature observed in EWSR1-FLI1low EwS cells [284] contributes to increased metastatic propensity of these cells to the bone, remains to be demonstrated as the tail vein injection-model used to identify increased metastatic potential of tumor cells with transient EWSR1-FLI1 knockdown is not well suited to study bone metastasis [285].