The invention relates to the fields of medicine, immunology, and oncology. More specifically, the invention relates to methods and compositions for inducing an immune response against a tumor in an animal subject. The invention provides that a lung cancer cell or other tumor cells, genetically modified to express a nucleic acid encoding CD80 (B7.1) and a nucleic acid encoding an HLA antigen, and method for stimulating an immune response to a tumor with the tumor cell so genetically modified. The invention additionally provides a method of inhibiting a tumor, including a cancer such as lung cancer, by administering an allogeneic tumor cell, for example a cancer tumor cell such as a lung cancer tumor cell, genetically modified to express a nucleic acid encoding CD80 (B7.1) and a nucleic acid encoding an HLA antigen.