LDLR, or Low-Density Lipoprotein Receptor, is a protein found on the surface of cells. It plays a crucial role in regulating cholesterol levels in the bloodstream by binding to LDL particles, which carry cholesterol. Once bound, the receptor helps internalize these particles, reducing the amount of cholesterol in the blood. The proper functioning of LDLR is essential for maintaining heart health. When LDLR is defective or absent, it can lead to high levels of LDL cholesterol, increasing the risk of cardiovascular diseases, such as heart attacks and strokes. Understanding LDLR is important for developing treatments for these conditions.