DNA damage-inducible transcript 3, also known as C/EBP homologous protein (CHOP), is a pro-apoptotic transcription factor that is encoded by the DDIT3 gene. It is a member of the CCAAT/enhancer-binding protein (C/EBP) family of DNA-binding transcription factors. The protein functions as a dominant-negative inhibitor by forming heterodimers with other C/EBP members, preventing their DNA binding activity. The protein is implicated in adipogenesis and erythropoiesis and has an important role in the cell's stress response. The regulation of CHOP expression plays an important role in metabolic diseases and in some cancers through its function in mediating apoptosis. The regulation of CHOP expression could be a potential approach to affecting cancer cells through the induction of apoptosis. In the intestinal epithelium, CHOP has been demonstrated to be downregulated under inflammatory conditions (in inflammatory bowel diseases and experimental models of colitis). In this context, CHOP seems to rather regulate the cell cycle than apoptotic processes. Mutations or fusions of CHOP (e.g. with FUS to form FUS-CHOP) can cause Myxoid liposarcoma.