yth ro po iet in ▁and ▁th rom b opo iet in . ▁ ▁The ▁M PL ▁gene ▁codes ▁for ▁a ▁protein ▁that ▁acts ▁as ▁a ▁re ceptor ▁for ▁th rom b opo iet in . ▁A ▁mut ation ▁in ▁that ▁gene , ▁known ▁as ▁a ▁W 5 1 5 ▁mut ation , ▁leads ▁to ▁the ▁production ▁of ▁an ▁ab normal ▁th rom b opo iet in ▁re ceptor ▁protein , ▁which ▁results ▁in ▁the ▁over production ▁of ▁ab normal ▁meg ak ary ocy tes . ▁The ▁ab normal ▁meg ak ary ocy tes ▁stim ulate ▁other ▁cells , ▁the ▁fib ro bl asts , ▁to ▁produce ▁col lagen ▁in ▁the ▁b one ▁mar row , ▁by ▁secre ting ▁P D G F ▁and ▁T G F - β 1 . ▁ ▁Mechan ism ▁My el of ib ros is ▁is ▁a ▁cl onal ▁ne op last ic ▁dis order ▁of ▁h emat opo ies is , ▁the ▁formation ▁of ▁blood ▁cell ular ▁components . ▁It ▁is ▁one ▁of ▁the ▁my el op rol ifer ative ▁dis orders , ▁dise ases ▁of ▁the ▁b one ▁mar row ▁in ▁which ▁excess ▁cells ▁are ▁produced ▁at ▁some ▁stage . ▁Production ▁of ▁cy tok ines ▁such ▁as ▁fib ro blast ▁growth ▁factor ▁by ▁the ▁ab normal ▁h emat opo iet ic ▁cell ▁clone ▁( part icular ly ▁by ▁meg ak ary ocy tes ) ▁leads ▁to ▁replacement ▁of ▁the ▁h emat opo iet ic ▁t issue ▁of ▁the ▁b one ▁mar row ▁by ▁connect ive ▁t