The indication that Brn-3a, a member of the Brn-3 family of type IV POU domain transcription factors is involved in the etiology of cancer has been demonstrated previously by the over expression of this transcription factor in CIN3 cervical lesions [13,14], neuroendocrine tumors [16], Ewing sarcomas [17] and prostate cancers [15]. The gene discussed is POU4F1; the disease is Ewing sarcoma.