After 8–10 more days in the presence of RA, Shh pathway agonists and neurotrophic factors, both HSF1 and human iPS-derived EBs contained Sox3+, Nkx6.1+ and Olig2+ motor neuron progenitors (a, b, d, e). Both HSF1 and human iPS cells were further able to produce differentiated Islet1 and βIII-tubulin-positive motor neurons within these EBs (c and f). Scale bar: a–f, 100μm.