CCAAT/enhancer-binding protein beta (C/EBPβ), a member of the C/EBP transcription factor family, plays a pivotal role in initiating adipogenesis and contributes to diabetes pathogenesis by regulating key metabolic enzymes such as phosphoenolpyruvate carboxykinase (PEPCK) in both adipose tissue and the liver. The gene discussed is CEBPB; the disease is diabetes mellitus.