For example, in some types of new medicines to treat human will. Experimental drugs have come up before, so the least amount of risk. So it must be basueksa and the possibility of a drug that will cure the most security.
As in the invention of new drugs of some kind in order to be used to treat humans. Animal experiments have taken the drug before, so the risk is minimal. Thus further studies and the possibility of a drug that is used to treat the most practical and safe.