Cynomolgus Monkey Transferrin Receptor 1 (TfR1/CD71) is a type II transmembrane glycoprotein encoded by the TFRC gene and a key regulator of cellular iron uptake. TfR1 binds transferrin-bound iron and mediates its internalization through receptor-mediated endocytosis, supporting cell growth, proliferation, and iron homeostasis. Due to its high sequence homology with human TfR1, cynomolgus TfR1 is widely used in crossreactivity studies, antibody discovery, blood-brain barrier (BBB) shuttle development, and preclinical safety assessment of TfR1-targeting therapeutics. This recombinant protein is suitable for antibody screening, binding characterization, epitope mapping, and translational research applications.