Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
One example is below.
Q: In 1582 the united provinces invited francis, duke of anjou to lead them; but after a failed attempt to take antwerp in 1583, the duke left the netherlands again. after the assassination of william of orange (10 july 1584), both henry iii of france and elizabeth i of england declined the offer of sovereignty. however, the latter agreed to turn the united provinces into a protectorate of england (treaty of nonsuch, 1585), and sent the earl of leicester as governor-general. this was unsuccessful and in 1588 the provinces became a confederacy. the union of utrecht is regarded as the foundation of the republic of the seven united provinces, which was not recognized by the spanish empire until the peace of westphalia in 1648.
A: In what year did francis, duke of anjou leave the netherlands?
Rationale: The generated question is perfect. Because the question is based on second sentence of the input passage and its answer is 1583.
Q: Embryonic neuroepithelia and adult subventricular zone (SVZ) stem and progenitor cells express nestin. We characterized a transgenic line that expresses enhanced green fluorescent protein (eGFP) specified to neural tissue by the second intronic enhancer of the nestin promoter that had several novel features. During embryogenesis, the dorsal telencephalon contained many and the ventral telencephalon few eGFP+ cells. eGFP+ cells were found in postnatal and adult neurogenic regions. eGFP+ cells in the SVZ expressed multiple phenotype markers, glial fibrillary acidic protein, Dlx, and neuroblast-specific molecules suggesting the transgene is expressed through the lineage. eGFP+ cell numbers increased in the SVZ after cortical injury, suggesting this line will be useful in probing postinjury neurogenesis. In non-neurogenic regions, eGFP was strongly expressed in oligodendrocyte progenitors, but not in astrocytes, even when they were reactive. This eGFP+ mouse will facilitate studies of proliferative neuroepithelia and adult neurogenesis, as well as of parenchymal oligodendrocytes.
A:
Which intermediate filament (IF) protein can be used as a non-specific marker of the neuronal precursor cells of the subventricular zone?