Differentiation of neural progenitor cells from hESCs by using small molecules. (a) Dorsomorphin, a small molecule inhibiting BMP signaling, was tested at various concentrations. (b) Morphology of hESCs transformed during the differentiation. Neural rosette structures appeared after 15 days of the differentiation prior to the generation of bipolar neural progenitor cells. (c) Gene expression analysis at different days of the differentiation. Pluripotency genes were downregulated, while neural progenitor genes were increased along the differentiation. GATA6 and Brachyury were not detected during neural differentiation. (d) Neural progenitor cells homogeneously expressed SOX1, PSA-NCAM, and NESTIN.