On the one hand, the people who support these experiments say that we must do tests on animals. For instance, many famous lifesaving drugs were invented in this way, and animal experiments may help us to find more cures in the future. Indeed, possibly even a cure for cancer and AIDS. Furthermore, the animals which are used are not usually wild but are bred especially for experiments. Therefore, they believe it is not true that animal experiments are responsible for reducing the number of wild animals on the planet.