PBX1 and myoepithelial tumor: In myoepitheliomas with t(1;22) and the EWSR1-PBX1 fusion gene, two transcripts were reported: one in-frame and, hence, supposedly pathogenetically crucial, with fusion between exon 9 (exon 8 in sequences with accession number X66899 and NM_005243) of EWSR1 and exon 5 of PBX1, the other out-of-frame with a fusion between exon 8 (exon 7 in sequences with accession number X66899 and NM_005243) of EWSR1 and exon 5 of PBX1; this one is presumably pathogenetically unimportant [9].