RNA-binding protein FUS, also called TLS (Fused in Sarcoma/Translocated in Sarcoma), is a protein that in humans is encoded by the FUS gene. FUS protein regulates different steps of gene expression, including transcription, splicing and mRNA transport.  Myxoid liposarcoma is a malignant lipogenic tumor that develops in deep soft tissues. Myxoid liposarcomas are the second-most common type of liposarcoma, representing 30–40% of all liposarcomas in the limbs, occurring most commonly in the legs, particularly the thigh, followed by the buttocks, retroperitoneum, trunk, ankle, proximal limb girdle, head and neck, and wrist.  Myxoid liposarcoma is characterized by the FUS-DDIT3 fusion oncoprotein that is proposed to function as an aberrant transcription factor. A characteristic chromosomal translocation leading to fusion of the DDIT3 and FUS genes on the 12q13 and 16p11 chromosomal regions is observed in 90% of myxoid liposarcoma cases. The result is the creation of a hybrid protein FUS-DDIT3 that causes malignant transformation by deregulating RNA transcription and thus adipocyte differentiation and cell cycle control.