text:  CHIR_2 2i-adapted mouse embryonic stem cells, CHIR99021(3 μM), PD0325901 and LIF are withdrawn for 24 hours treatment: CHIR99021; cell line: 2i-adapated Ctnnb1-Biotin-3xFLAG knock-in ESC line (Ctnnb1-BioFLneo;BirA ESC)