An international team of scientists mapped the genomes of 100 triple negative breast cancer tumors, the deadliest form of the disease, and discovered that no two genomes were similar. “Seeing these tumors at a molecular level has taught us we’re dealing with a continuum of different types of breast cancer here, not just one,” Steven Jones, co-author of this study, said. “The genetic diversity of these tumors, even though they’re clinically similar, probably explains why they are so difficult to treat.” Triple negative breast cancer does not have surface cell receptors for estrogen, progesterone and herceptin, all linked to breast cancer. Of women who develop breast cancer, 16 percent will have triple negative breast cancer. It is considered the most deadly form because it does not respond well to modern drug therapies, which target those receptors.