POU5F1 and teratoma: The isolated EF-iPSCs showed high expression of pluripotency markers, such as OCT4, NANOG, TRA-1-60, TRA-1-81, SSEA3, SSEA4, and AP (Fig. 4a, b), and underwent differentiation into three germ layers in vitro and typical teratoma formation in vivo (Fig. 4c, d).