ATF1 and histiocytoma, Angiomatoid fibrous: Furthermore, although EWSR1::ATF1 is associated with multiple tumors, including angiomatoid fibrous histiocytoma, myoepithelial tumors, hyalinizing clear cell carcinoma, and CCS-like tumors of the gastrointestinal tract (45, 46), SOX10 expression is relatively specific to CCS (45, 47, 48).