op rote in ▁B ▁( A po B ) ▁is ▁a ▁protein ▁that ▁in ▁humans ▁is ▁encoded ▁by ▁the ▁AP OB ▁gene . ▁ ▁Function ▁ ▁Apol ip op rote in ▁B ▁is ▁the ▁primary ▁ap ol ip op rote in ▁of ▁ch yl omic rons , ▁V LD L , ▁ID L , ▁and ▁L DL ▁particles ▁( LD L ▁- ▁known ▁commonly ▁by ▁the ▁mis nom er ▁" bad ▁ch ol ester ol " ▁when ▁in ▁reference ▁to ▁both ▁heart ▁disease ▁and ▁v asc ular ▁disease ▁in ▁general ), ▁which ▁is ▁responsible ▁for ▁carrying ▁fat ▁mole cules ▁( lip ids ), ▁including ▁ch ol ester ol , ▁around ▁the ▁body ▁( with in ▁the ▁water ▁outside ▁cells ) ▁to ▁all ▁cells ▁within ▁all ▁t issues . ▁While ▁all ▁the ▁functional ▁roles ▁of ▁A po B ▁within ▁the ▁L DL ▁( and ▁all ▁larger ) ▁particles ▁remain ▁somewhat ▁unclear , ▁it ▁is ▁the ▁primary ▁organ izing ▁protein ▁( of ▁the ▁entire ▁complex ▁shell ▁en clos ing / car ry ing ▁fat ▁mole cules ▁within ) ▁component ▁of ▁the ▁particles ▁and ▁is ▁absolutely ▁required ▁for ▁the ▁formation ▁of ▁these ▁particles . ▁What ▁is ▁also ▁clear ▁is ▁that ▁the ▁A po B ▁on ▁the ▁L DL ▁particle ▁acts ▁as ▁a ▁lig and ▁for ▁L DL ▁re cept ors ▁in ▁various ▁cells ▁throughout ▁the ▁body ▁( i . e ., ▁less ▁formally , ▁A po B ▁indicates ▁fat ▁carrying ▁particles ▁are ▁ready ▁to ▁enter ▁any ▁cells ▁with ▁A po B ▁re cept ors ▁and ▁deliver