EWSR1::ATF1-driven mesenchymal entities encompass phenotypically diverse mesenchymal neoplasms with melanocytic (clear cell sarcoma of tendon and aponeuroses (CCS)) [17], neuroectodermal-like (malignant gastrointestinal neuroectodermal tumor (MGNET) [8, 9], and undefined/unknown (angiomatoid fibrous histiocytoma (AFH) [18], primary pulmonary myxoid sarcoma [19], and primary intracranial myxoid sarcoma [20])) histogenesis/phenotype. This evidence concerns the gene ATF1 and histiocytoma, Angiomatoid fibrous.