iPSC line (DF19-9), and were cultured independently for at least 20 passages. Before cell harvest aliquots of cells were assayed for OCT4 expression by flow cytometry as described previously33,34. Cells were also submitted to the WiCell Cytogenetics Laboratory to confirm normal karyotype. For BMP4 differentiation, H1 or FF-iPSC 19.11 cells were grown in 10-cm2 dishes (approximately 1 × 107 cells per dish) in feeder-free conditions on Matrigel using mTeSR1 media containing 50 ng ml−1 BMP4 for 5 days (RND systems).
