EWSR1 and sarcoma: The group characterized by relatively simple karyotypes includes sarcomas with chromosomal translocations leading to fusion oncogenes (e.g., FUS/EWSR1-DDIT3 and PAX3/7-FOXO1, which characterize myxoid liposarcoma (MLS) and alveolar rhabdomyosarcoma (ARMS), respectively) and oncogene-mutated sarcomas (e.g., KIT, PDGFRA, RAS and BRAF mutations in GIST).