Personalized medicine is the phrase on everyone's lips, as researchers work on ways to match the right medicines with the right patients for the best results. Biotech firm Cellular Dynamics International — cofounded by stem cell pioneer James Thomson — is trying to take that process one step further by growing induced pluripotent heart stem cells from blood samples and selling them to researchers and the pharmaceutical industry for everything from studies on how the cells work to how they react to certain drugs, reports Technology Review's David Ewing Duncan. Because the cardiomyocytes derived from iPS cells are alive, researchers say, they react differently to medicines than cadaver cells do, making it less likely that drugs with cardiotoxic profiles will make it to market. CDI plans to start selling iPS-generated liver, brain, and blood cells as well, Duncan says. The hope many researchers have, he adds, is that, eventually, iPS-based tests could be performed on individual patients to see how they would react to a particular drug before it is prescribed.