We have recently demonstrated that the use of human embryonic stem mesenchymal progenitors (hES-MP) is important in the generation of Clear Cell Sarcoma (CCS) and Angiomatoid Fibrous Histiocytoma (AFH) models harboring the EWSR1::ATF1/CREB1 translocations [13]. Here, CREB1 is linked to clear cell sarcoma.