IiBGM zizaliswe yiiron eneproteni kwimbewu ebomvu yegazi. Ngesingesi ke kuthiwa yihaemoglobin. Singatsho ngelipheleleyo okokuba yiproteni. Yenzelwe ukuba ithwale umoya omninzi ococekileyo iwusasaze kuwo wonke umzimba. Njengoko sele sitshilo, le haemoglobin ine''iron'' kuyo. Xa zizombini ke iiiron kunye nalo moya ucocekileyo ziyitsho ibebomvu le haemoglobin ngombala. Yhiyo le nto igazi silibona libomvu nje. Kukho into ekuthiwa yi''Erythropoietin'' ekuyeyona ikhuthaza ukwenzeka kwale mbewu ibomvu egazini. Uhlobo lwegazi amajoni akhutshwa yinkqubo yangaphakathi emzimbeni ukuba alwe nokuyingozi okungena emzimbeni athwalwa apha kumphezulu wembewu yegazi ebomvu.