Another argument that proponents for animal testing have is that it will guarantee improvements in multiple fields that will better society dramatically. They claim that animals are very similar to humans, so the results can translate to humans very accurately. Scientists say that “chimpanzees share 99% of their DNA with humans, and mice are 98% genetically similar to humans. All mammals, including humans, are descended from common ancestors, and all have the same set of organs that function in essentially the same way with the help of a bloodstream and central nervous system” (“Animal Testing”). Furthermore, they claim that there are various examples of important advancements due to the use of animals in research. For instance, there have been many improvements in cancer research due to animal research. New therapies with fewer side effects are being developed and new drugs such as Tamoxifen have already saved thousands of lives. Advancements in Leukemia and HIV therapies have also benefited from animal research, as new drugs such as Gleevec are more effective and less harmful for the patient ("Animal Research Benefits:").