“…Legend of MERLIN and the Quest for Cardiac Lineage Commitment Rich Gang Li , PhD; James F. Martin , MD, PhD I n this issue of Circulation, Lee et al 1 report an indepth study of in vitro cardiomyocyte differentiation using human embryonic stem cells. The authors used genome-wide CRISPR screening to determine essential genes for early cardiac lineage commitment and found perturbation of NF2 to completely abolish cardiomyocyte differentiation in a human pluripotent stem cell culture system.…”