Mousetransferrin receptor protein 1, also known as transferrin receptor, Trfr, p90,CD71 and TFRC, is a single-pass type II membrane protein which belongs tothe peptidase M28 family and M28B subfamily. TFRC / CD71 is amembrane-bound protein expressed in larger amounts in proliferating. Thespecific expression of TFRC can represent a diagnostic tool or a therapeutictarget in solid tumours expressing this antigen. Transferrin receptor isnecessary for development of erythrocytes and the nervous system. TFRC / CD71is regulated by cellular iron levels through binding of the iron regulatoryproteins, IRP1 and IRP2, to iron-responsive elements in the 3-UTR.Up-regulated upon mitogenic stimulation. TFRC / CD71 represents a marker ofmalignant transformation in the pancreas that could be applied as potentialdiagnostic and therapeutic target.