The ESC-derived TSLCs (passage number 18) were dissociated by TrypLE select into single cells and suspended in PBS containing DRAQ-7. DRAQ-7-negative live cells were isolated as single cells using a Flow cytometer. From these cells, total RNAs were extracted using A Chromium Single Cell 3' Library & Gel Beads Kit v3.1 (10x Genomics) following the manufacturer's protocol. Sequencing libraries were constructed using A Chromium Single Cell 3' Library & Gel Beads Kit v3.1 (10x Genomics) following the manufacturer's protocol.