Cardiomyocytes, the workhorse cells that make up the beating heart, can now be made cheaply and abundantly in the laboratory. Writing this week (May 28, 2012) in the Proceedings of the National Academy of Sciences, a team of Wisconsin scientists describes a way to transform human stem cells -- both embryonic and induced pluripotent stem cells -- into the critical heart muscle cells by simple manipulation of one key developmental pathway. The technique promises a uniform, inexpensive and far more efficient alternative to the complex bath of serum or growth factors now used to nudge blank slate stem cells to...