EWSR1 and primitive neuroectodermal tumor: The role of Fli-1 has been investigated in Ewing sarcoma and primitive neuroectodermal tumors; this potential role is implicated by the presence of a specific translocation t(11;22) that resulting in a fusion of EWS on chromosome 22 to FLI1 on chromosome 11 in 90% of cases of these tumors [11, 12].