HLA-DMA and neoplasm: However, when MHC II is expressed without coexpression of Ii and HLA-DM, such as in MHC II-transduced or -transfected tumour cells, they may become potent immunogens by presenting endogenous antigens, provided that B7 expression is induced following MHC II engagement or expressed through cotransfection or cotransduction of the B7 gene(s) (Baskar et al, 1996; Armstrong et al, 1997).