SLCO1B1, also known as Solute Carrier Organic Anion Transporter Family Member 1B1, is a membrane-bound transporter protein mainly found in the liver. It plays a crucial role in the uptake of various endogenous and exogenous compounds—including bile acids, hormones, drugs, and toxins—from the bloodstream into liver cells (hepatocytes). One of its primary functions is facilitating the hepatic uptake of bile acids, which is vital for maintaining bile acid balance and bile production. By transporting bile acids across the sinusoidal membrane of hepatocytes, SLCO1B1 aids in their clearance from the blood and integration into bile.