Possibly, this coexpression of MHC II and B7 increases the immunogenicity of the tumour as has been demonstrated in in vitro studies and mouse tumour models (Becker et al, 1993; Chen et al, 1994; Baskar et al, 1996; Pulaski and Ostrand-Rosenberg, 1998; Ostrand-Rosenberg et al, 1999). The gene discussed is CD80; the disease is neoplasm.