FIGURE 2.

A simplified schematic representation of a proposed endogenous neural stem cell (NCS) lineage. Within the central nervous system, the proposed lineage suggests two types of NSCs are present. Primitive NSCs (pNSCs) are a population of rare, leukemia inhibitory factor (LIF) responsive cells that give rise to more abundant definitive NSCs (dNSCs). dNSCs are responsive to EGF and FGF2 (EFH). NSC progeny (progenitor cells) give rise to neurons, astrocytes, and oligodendrocytes upon differentiation. This pathway is exploited for ESC‐ and iPSC‐based generation of NSCs, neurons and glia. Direct reprogramming allows somatic cells to enter the NSC or later stage without passing through the pluripotent state