Emergence of undifferentiated colonies from mouse embryonic stem cells undergoing differentiation by retinoic acid treatment

Lioudmila V. Sharova, Alexei A. Sharov, Yulan Piao, Carole A. Stagg, Tomokazu Amano, Yong Qian, Dawood Dudekula, David Schlessinger, Minoru S.H. Ko