that human cortical interneuron precursors have a similar capacity for tangential migration as their mouse counterparts. However, a distinctive feature in hESC-derived cortical interneurons was the persistent expression of NKX2.1. Nkx2.1 is extinguished in mouse cortical interneuron precursors by the time they leave the MGE prior to entering the cortex (Marin et al., 2000). Our in vitro data are consistent with findings in the human neocortex in vivo showing the presence of postmitotic NKX2.1+ neurons (Fertuzinhos et al., 2009). However, our data do not rule out the possibility that a subset of our human ESC-derived cells correspond to striatal interneurons, as those share markers of cortical interneurons in the mouse while retaining NKX2.1 expression (Marin et al., 2000).
