To determine the effects of immune and endothelial cell-released factors on ADA iso-enzyme activities on the surface of breast cancer cells, we incubated human MDA-MB-231 triple negative breast cells with the cell-free medium obtained from the culture of human THP-1 monocytes/macrophages, Jurkat E6.1 lymphocytes or human lung microvascular endothelial cells (HULEC). Here, ADA is linked to breast cancer.