FABP3 (H-FABP, mammary-derived growth inhibitor) is an intracellular fatty acid-binding protein that participates in the uptake, intracellular metabolism and transport of long-chain fatty acids. FABP3 is generally involved in modulating cell growth and proliferation, and functions to arrest the growth of mammary epithelial cells and thus is considered a potential breast cancer tumor suppressor. It is a useful serum marker for myocardial infarction, acute coronary syndrome and heart injury, and it is a prognostic marker of increased mortality in cardiac diseases and acute pulmonary embolism. FABP3 is overexpressed in non-small cell lung cancer, where it is also an indicator of poor prognosis. In immunohistochemistry of normal tissue, FABP3 has cytoplasmic positivity primarily in heart muscle. References: The Journal of Pathology. 170 (1): 59–65, PMID: 8326460; Journal of the American College of Cardiology. 2007. 50 (21): 2061–7, PMID: 18021874; Intl J Clin Chem. 2006. 371 (1–2): 117–23, PMID 16698008; Oncotarget. 2016 Jul 19; 7(29): 46253–46262, PMID: 27323829;