The agent of malaria has been found in the greater spot-nosed monkey, also known as putty-nosed monkey (Cercopithecus nictitans), a small African primate derived from a line different to that of humans, gorillas and chimpanzees. This discovery challenges current thinking on the origin of the parasite and introduces a key element in the fight against malaria: knowing how it has adapted to the human species will make it possible to target its weaknesses.