library_construction_protocol: EpiSCs were collected using collagenase and Accutase as per the EpiSC 48 hours post-thaw. The resulting cell suspension was used for 10x scRNA-seq (10x Genomics, Single Cell 3′ Kit v3.1, dual index) following the manufacturer's directions. We combined four cell villages in equal number to a total of 30,000 cells per sequencing channel. We targeted a sequencing depth of 40,000 reads per cell (1.2e9 total reads per sequencing channel) for genetic demultiplexing. Libraries were prepared according to manufacturer's instructions (10x Genomics, Single Cell 3′ Kit v3.1, dual index).