Personalized medicine sounds awesome.
For the last 100 years, drug development consisted of small-molecule treatments aimed at mass audiences. For some patients it worked, for some it didn't; sometimes we knew why, often we didn't; and gigantic pharmaceutical companies grew rich. And then, at the turn of the last century, we began to understand a bit more about human genetics—what makes us all different. We knew not only how many genes there were but also what many of them did. We still don't know what to do with all this information, but we are getting better. And just now we are beginning to translate what we know about human genetics to make medicine. Personalized medicine. We are learning not only what "works" but also what makes us susceptible to illness by deciphering where genetics may load the gun and the environment pulls the trigger, and then devising personalized therapies.
Related: "The history of medicine will seem blunt and random compared with what's coming next" and "New era in the war on cancer".