library_construction_protocol: RNA was extracted from hiPSC-derived cells using the QIAcube and the RNeasy Plus Mini Kit (QIAGEN). RNA quality was ascertained with the TapeStation (Agilent), and only samples with a RIN>9.0 value were used for sequencing. Sequencing libraries were made with the PrepX DNA library kit (Takara bio) using the Apollo system (Takara bio). Quality control for the libraries was performed using the KAPA library quantification kit (Roche) and the TapeStation (Agilent). Sequencing libraries were barcoded, pooled and sequenced on a HiSeq 2500 (Illumina) with single-end 150bp reads.