Physically and mentally, humans differ considerably from their closest relatives, the apes. However, the differences are not in the genes, because human genes are almost identical to those of monkeys, but rather in the use of genes. This was reported by an international team of researchers led by Svante Pääbo from the Max Planck Institute for Evolutionary Anthropology in Leipzig. The scientists had analyzed 0.1 percent of the chimpanzee genome and found in the study of about three million base pairs that 98.7 percent of the ape gene is identical to that of humans. In contrast, the researchers found significant differences in gene activity when comparing chimpanzees, orangutans, rhesus monkeys, and humans. The differences are most obvious in the brain, less pronounced in liver and blood cells. From this, the researchers conclude that in the course of evolution from apes to humans, the use of genes in the liver has changed less than that of genes in the brain. Now scientists are working to identify the causes of these differences. Especially for human medicine, these findings are of great importance, as they could help to better understand the genetic basis for susceptibility to AIDS, malaria or Alzheimer's disease. Thus, chimpanzees are resistant to the immune deficiency disease AIDS. In addition, these primates Alzheimer's and malaria as well as breast cancer, colon cancer or lung cancer are much rarer than in humans.