STAB1 (stabilin 1) encodes a multifunctional scavenger receptor that plays critical roles in lipid metabolism, immune regulation, and vascular biology. The protein functions as a scavenger receptor for acetylated low-density lipoprotein and is involved in plasma protein clearance, with STAB1 variants identified as pleiotropic regulators affecting 77 different plasma protein levels 1. STAB1 demonstrates significant involvement in lipid homeostasis, with damaging variants found in individuals with hypoalphalipoproteinemia (low HDL-cholesterol levels) 2. In immune contexts, STAB1 promotes macrophage polarization toward the immunosuppressive M2 phenotype and is highly expressed in lipid-associated macrophages that contribute to immune suppression in triple-negative breast cancer 3. The protein also facilitates cancer progression through activation of the IKK/NF-κB pathway, promoting acute myeloid leukemia cell proliferation and survival 4. In vascular development, STAB1 is expressed in liver sinusoidal endothelial cells and contributes to specialized vessel formation 5. Therapeutically, targeting STAB1 shows promise, as antibody-mediated inhibition enhances chemotherapy response in ovarian cancer by repolarizing macrophages toward anti-tumor phenotypes 6. STAB1 also serves as a potential diagnostic biomarker for metabolic dysfunction-associated steatohepatitis 7.