RBM20 and cardiac hypertrophy: We performed differential expression testing on all the cell types and found several genes that were differentially expressed between mGFP+ and mTd+ cells, including genes implicated in regulation of cardiac function (Mhrt and Sema3a) (49,50), cell-cycle regulation and cardiac hypertrophy (Ccnd3) (51), and regulation of splicing in cardiomyocyte-specific genes (Rbm20) (52).