REPIN1 (replication initiator 1) is a zinc finger protein and sequence-specific double-stranded DNA-binding protein that preferentially binds AT-rich and T-rich DNA sequences and facilitates DNA bending 12. Beyond its classical role in DNA replication initiation, REPIN1 functions as a transcriptional regulator with significant metabolic importance. It regulates expression of genes involved in fatty acid transport (SCARB1/CD36), glucose transport (GLUT1/GLUT2), and lipid droplet formation in adipocytes and hepatocytes 34. REPIN1 also regulates LCN2, influencing iron metabolism and apoptosis pathways 5. Functionally, REPIN1 is highly expressed in liver and adipose tissue, correlating with adipocyte size and body fat mass 67. REPIN1 deficiency in adipose tissue improves insulin sensitivity and glucose tolerance while reducing body weight and lipid accumulation 48. Disease relevance includes osteoporosis, where REPIN1 promotes osteoblast apoptosis through iron metabolism regulation via LCN2 5, nonalcoholic fatty liver disease (NAFLD), where REPIN1 deletion variants associate with lower disease severity 9, and preeclampsia, where reduced REPIN1 expression associates with decreased risk 10. These findings suggest REPIN1 represents a therapeutic target for metabolic and iron-related disorders.