BAMBI (BMP and activin membrane-bound inhibitor) is a transmembrane glycoprotein that functions as a pseudoreceptor for TGF-β signaling 1. While structurally similar to type I TGF-β receptors, BAMBI lacks the intracellular serine/threonine kinase domain, enabling it to act as a negative regulator of TGF-β and BMP signaling pathways 1. BAMBI also positively regulates canonical Wnt/β-catenin signaling and serves as a target gene of β-catenin transcription 2. Mechanistically, BAMBI regulates glucose and lipid metabolism, inflammatory responses, cell proliferation, and differentiation 1. In hepatocellular carcinoma, BAMBI mediates the suppressive effects of PPARGC1A on tumor progression by regulating ACSL5 through TGF-β/SMAD signaling and controlling ferroptosis-related cell death 3. In liver fibrosis, EZH2 epigenetic inhibition upregulates BAMBI as a TGF-β pseudoreceptor, reducing hepatic stellate cell activation 4. Clinically, abnormal BAMBI expression contributes to multiple pathologies including obesity, diabetes, and cancer 1. In colorectal cancer, BAMBI expression within cancer stem cell signatures correlates with patient prognosis 5. Additionally, reduced BAMBI expression in cumulus cells associates with impaired oocyte maturation in polycystic ovarian syndrome 6. These findings support BAMBI as a potential biomarker and therapeutic target across multiple disease contexts.