In solid tumors, this approach was used to identify the WWTR1-CAMTA1 and YWHAE-FAM22A/B chimeric genes in epithelioid hemangioendothelioma and in high-grade endometrial stromal sarcomas, respectively (17,18), ZC3H7-BCOR in endometrial stromal sarcomas (19), IRF2BP2-CDX1 in a mesenchymal chondrosarcoma (20), and EWSR1-YY1 in a subset of mesotheliomas (21). This evidence concerns the gene YY1 and endometrioid stromal sarcoma.