although the 129 mouse produces no demonstrable leukemia virus such as that found in the akr strain , it was soon realized that g ( ix ) antigen must in some way be related to mulv , because productive infection with mulv is frequently associated with appearance of g ( ix ) antigen on cells that are genotypically g ( ix- ) , most notably on mulv-infected rat cells , or cells that belong to other differentiation pathways ( 1 ) .
C0007634
cells
C0007589
differentiation