DFFA (DNA fragmentation factor subunit alpha), also known as DFF45, is a nuclear and cytoplasmic protein that functions as an inhibitor of the caspase-activated DNase DFF40, thereby negatively regulating apoptotic DNA fragmentation and the execution phase of apoptosis 1. Beyond its classical apoptotic role, DFFA is part of the CIDE protein family, which has been redefined as regulators of lipid droplet dynamics and fat metabolism rather than purely apoptotic factors 1. DFFA-like effector proteins (particularly CIDEA, CIDEB, and CIDEC/FSP27) associate with lipid droplets and regulate their fusion and expansion, thereby controlling substrate utilization in adipocytes 2. In metabolic contexts, CIDEA expression is decreased in obese humans and increased following weight loss, suggesting a role in metabolic homeostasis and obesity-related complications 3, 4. Dysregulation of DFFA-related proteins contributes to multiple diseases: CIDEC elevation is associated with diabetic cardiomyopathy through metabolic disturbance and insulin resistance 5, while aberrant DFFA expression patterns correlate with gastrointestinal cancer progression 6. Additionally, DFFA has been identified in the neuroblastoma tumor suppressor region 1p36.2, with rare variants detected in some tumors 7. These findings establish DFFA as a multifunctional protein regulating both apoptosis and metabolic lipid dynamics.