Having more cells usually puts one at a higher risk for cancer - but not for the elephant. Despite packing 100 times as many cells as humans, this towering animal can keep cancer at bay thanks to extra copies of a tumor-fighting gene. Researchers found that Asian elephants harbor 30 to 40 copies of the gene that encodes the
protein p53, one of the most important mechanisms for preventing cancer and maintaining cell division. If cells have DNA damage that could spawn tumors, p53 prevents them from dividing until they make repairs or spurs them to commit suicide. In contrast, humans sport only two copies of the gene for p53, and so does elephants’ closest living relative, the rock hyrax. The extra copies probably accumulated millions of years ago as the gene was accidentally duplicated many times in the ancestors of elephants, the researchers suggest.
Source: http://news.sciencemag.org/plants-animals/2015/10/how-elephants-crush-cancer
