EWSR1 and neoplasm: RT-PCR with all four primer combinations—EWSR1-879F/PBX3-1198R1, EWSR1-986F/PBX3-1032R1, EWSR1-879F/PBX3-1032R1, and EWSR1-986F/PBX3-1198R1—amplified cDNA fragments strongly suggesting the presence of an EWSR1-PBX3 fusion transcript in the examined tumor (Fig 3A).