SOX2 and teratoma: The isolated hiPSC colonies were cultured in E8 culture medium (Fig. 1a), and further verified by expression of pluripotency markers NANOG, SOX2, OCT4 and TRA-1-60 (Fig. 1b and Additional file 2: Figure S1A), and formation of embryoid bodies (EBs) (Additional file 2: Figure S1B) and teratoma with three germ layers (Fig. 1c, d).