Fatty Acid Binding Protein 3 (FABP3), also known as Heart-type FABP (H-FABP), is a small cytoplasmic protein primarily found in cardiac and skeletal muscle cells. It plays a crucial role in the intracellular transport and metabolism of long-chain fatty acids. Due to its rapid release into circulation following cellular damage, FABP3 serves as an early and sensitive biomarker for myocardial injury, often detected sooner than traditional markers like troponins, making it valuable in the early diagnosis of acute coronary syndromes.