The development and progress of human medicine not only benefit from the hard work of scientists, but also from the silent sacrifice of experimental animals  Before drug development into the clinical, we need to do a lot of animal experiments to explore the efficacy, toxicity, safe dose of drugs  However, there are many differences between human beings and rats, pigs, dogs, rabbits and other animals after all
In 1957, a pregnancy response drug called thalidomide was put on the market after being tested on rats. After a period of time, it was discovered that thalidomide can cause malformations in human fetuses, but it will not cause teratogenicity to rat fetuses.
 Even if we have a correct understanding of the physiological structure of animals and the law of drug reaction, we can not easily and blindly transfer the result of our understanding to human beings