We have made considerable progress on this project, which is aimed at understanding how genes are controlled during the conversion of human stem cells into heart cells. We have been able to use advanced techniques that allow us to make millions of human heart cells in a dish from “Induced Pluripotent Stem Cells” (known as iPS cells), which are cells derived from skin cells that have properties of embryonic stem cells. We are now using genome engineering techniques to insert a mutation that is associated with human congenital heart defects. We are now starting to map the chromatin marks that will tell us how heart genes are turned on, while genes belonging to other cell types are kept off. This “blueprint” of a heart cell will help us understand how to make better heart cells to repair injured hearts, and will allow us to model human congenital heart disease in a human experimental system.