Serum ferritin: Past, present and future

BackgroundSerum ferritin was discovered in the 1930s, and was developed as a clinical test in the 1970s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in diagnosing and monitoring these diseases.Scope of reviewIn this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool.Major conclusionsAlthough many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer.General significanceSerum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights.