False statement about hemoglobin structure?

Each hemoglobin molecule is made up of:- (i) Non-protein part, i.e. heme; and (ii) Globin, which has 4 polypeptide chains (2 pairs of similar polypeptide chains). Iron of hemoglobin is in the ferrous state which lies in the center of the porphyrin ring. Myoglobin and the β-subunits of hemoglobin share almost identical structures.