Promoter histone modifications were further shown to mediate tumor endothelial cell anergy, as adhesion molecule expression was shown to be epigenetically repressed in tumor endothelial cells, and that DNA methyltransferase and histone deacetylase inhibitors which have angiostatic activity could re-induce expression of the ICAM-1 gene by reversal of histone modifications in the ICAM-1 promoter, thereby restoring leukocyte-vessel wall interactions and leukocyte infiltration (51). The gene discussed is ICAM1; the disease is neoplasm.