class i histocompatibility antigens ( hla ) and transferrin receptors , 2 well characterized integral membrane proteins , are uniformly distributed on the cell surface of undifferentiated ht29-18 cells , but acquire a polarized distribution during differentiation , localized on the basolateral membranes and absent from the apical surface .
C0019629
class i histocompatibility antigens
C0019628
hla