Abstract
Lactoferrin is an iron‐binding protein present in various secretions as well as in the neutrophilic granulocyte series. A radioimmunodiffusion method has been used for the measurement of this protein in serum.Normal sera contain up to 3.5 mg/l of lactoferrin. Elevated concentrations were encountered in patients with chronic myelocytic leukaemia and polycythaemia vera.