DDIT3 is a C/EBP-family transcription factor implicated in adipocyte differentiation. Chromosomal rearrangements involving the DDIT3 gene, located on chromosome 12q13, are common in myxoid liposarcomas (MLS) and have also been identified in round cell (RC) and mixed liposarcomas (combined myxoid and round cell). A unique translocation t(12;16)(q13;p11) results in transcriptional deregulation of the DDIT3 gene, and is present in >95% of MLS cases. A rare case of MLS bearing a variant chromosomal translocation t(12;22)(q13;q12) resulting in EWS-DDIT3 fusion gene has also been described.
Gene rearrangements involving the DDIT3 (CHOP) gene region at 12q13 is regarded as a diagnostic marker for myxoid/round cell liposarcoma.