Hp, Gc, Tf
The classical serum-protein polymorphism panel: haptoglobin (binds free haemoglobin; Hp1-1, Hp2-1, Hp2-2 phenotypes), group-specific component (vitamin D binding protein, Gc1F / Gc1S / Gc2 alleles) and transferrin (iron-carrier, TfC / TfB / TfD variants).