▁or ▁elimin ating ▁any ▁problems ▁with ▁re jection ▁when ▁the ▁stem ▁cells ▁were ▁trans pl anted ▁for ▁treatment . ▁For ▁example , ▁to ▁treat ▁a ▁man ▁with ▁Park inson ' s ▁disease , ▁a ▁cell ▁nucle us ▁from ▁one ▁of ▁his ▁cells ▁would ▁be ▁trans pl anted ▁by ▁SC NT ▁into ▁an ▁egg ▁cell ▁from ▁an ▁egg ▁don or , ▁creating ▁a ▁unique ▁line age ▁of ▁stem ▁cells ▁almost ▁identical ▁to ▁the ▁patient ' s ▁own ▁cells . ▁( There ▁would ▁be ▁differences . ▁For ▁example , ▁the ▁mit och ond rial ▁DNA ▁would ▁be ▁the ▁same ▁as ▁that ▁of ▁the ▁egg ▁don or . ▁In ▁comparison , ▁his ▁own ▁cells ▁would ▁carry ▁the ▁mit och ond rial ▁DNA ▁of ▁his ▁mother .) ▁ ▁Pot entially ▁millions ▁of ▁patients ▁could ▁benefit ▁from ▁stem ▁cell ▁ther apy , ▁and ▁each ▁patient ▁would ▁require ▁a ▁large ▁number ▁of ▁don ated ▁eggs ▁in ▁order ▁to ▁successfully ▁create ▁a ▁single ▁custom ▁th era pe ut ic ▁stem ▁cell ▁line . ▁Such ▁large ▁numbers ▁of ▁don ated ▁eggs ▁would ▁exceed ▁the ▁number ▁of ▁eggs ▁currently ▁left ▁over ▁and ▁available ▁from ▁cou ples ▁trying ▁to ▁have ▁children ▁through ▁assist ed ▁re product ive ▁technology . ▁Therefore , ▁health y ▁young ▁women ▁would ▁need ▁to ▁be ▁induced ▁to ▁sell ▁eggs ▁to ▁be ▁used ▁in ▁the ▁creation ▁of ▁custom ▁stem ▁cell ▁lines ▁that ▁could ▁then ▁be ▁purchased ▁by ▁the ▁medical ▁industry ▁and ▁sold ▁to ▁patients . ▁It ▁is ▁so ▁far ▁unclear ▁where ▁all ▁these ▁eggs ▁would ▁come ▁from . ▁ ▁St