Adult mammalian <a></a><a>cardiomyocytes </a>(CMs, or heart muscle cells) have little, if any, ability to proliferate in response to injury, and after myocardial infarction this defect underlies the poor regenerative ability of human hearts. In contrast, early stage of CMs (such as fetal CMs) still have some ability to proliferate, and we seek to identify novel gene regulators as potential therapeutic targets for heart regeneration. Here we use human pluripotent stem cells (hPSCs) as an in vitro human model to investigate the roles of emerging long non-coding RNAs (lncRNAs), with the lengths of over 200 nucleotides are able to be transcribed but not translated into protein, for heart regeneration. With public available RNA-sequencing data, we identified several human genes, including lncRNAs, that are highly enriched in fetal CMs. We generated targeted gene knockout hPSC lines using CRISPR/Cas9-mediated genome editing and will use them to study the roles of selected genes in regulating CM proliferation. To identify more therapeutic targets, we also generated a fluorescence ubiquitination cell cycle indicator (FUCCI) reporter cell line that express either green (indicating dividing cells) or red fluorescence (indicating non-dividing cells), on which we’ll perform unbiased genome-wide screening to identity genes that regulate CM proliferation. High-throughput chemical screening will also be performed on FUCCI reporter lines to identify potential therapeutic drugs for heart regeneration.