Scientists usually conduct a variety of in vitro and in vivo studies on rodent and their cell cultures and they show the concentration of a particular drug is effective against the disorder for both in vitro and in vivo for the rodents. My question is how do they translate that to a dose for the same disorder in humans. For instance I was reading an article that said X uM drug concentration was effective in bringing the desired effect in vitro and Y uM was effective in bringing about the same effect that is ameliorating the said condition. What will be the dosage that will be effective to bring about the same change based on these studies? In short, how do scientists proceed from these studies after the optimal dose has been established in rodents? Thank you in advance for your replies.