TNNT2 and neoplasm: By labelling with the myocardial marker cTnT and the pluripotent marker TRA-1-60, more than 80 % of the cells adopted the cardiomyocyte fate (Fig. S4A) while less than 1 % remained positive for TRA-1-60 (Fig. S4B) on day 15 post-differentiation, which suggested a minimal risk of tumor formation in the further in vivo applications.