Chen et al. (93, 94) studied B7-homolog 3 (B7-H3) and B7-homolog 4 (B7-H4) expressed on macrophages in lung cancer stroma and found that lung cancer cells and TAM-related B7-H3/B7-H4 were strong inhibitors of T cell effect, both of which acted in the form of costimulatory. This evidence concerns the gene VTCN1 and lung carcinoma.