(Cell Stem Cell 22, ■■■–■■■; May 3, 2018)
In the original version of our paper published online on April 12, 2018, an internal Cell Press production error caused the Received date of the paper to be wrongly displayed as May 17, 2017, and this mistake was unfortunately not caught during the proof correction process. The correct Received date of our paper is 2 months earlier, March 17, 2017. Both the online and print versions of the manuscript have now been edited to display the proper date. We, along with the Cell Press production staff, apologize for the confusion.