Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[Q]: Once acquired, Epstein-Barr virus (EBV), a latent virus, remains in the body for what appears to be the lifetime of the human host. Circumstantial data suggest EBV is involved in clinical disease including malignancies far more often than previously recognized. A serologic test for early antigen (EA) is more specific for diagnosing active EBV disease than the monospot or heterophile test. A case study of active Epstein-Barr infection is reported showing persistently elevated early antigen titers prior to and following malignant transformation.
[A]: Which virus can be diagnosed with the monospot test?


[Q]: Selenoproteins contain the 21st amino acid selenocysteine which is encoded by an inframe UGA codon, usually read as a stop. In eukaryotes, its co-translational recoding requires the presence of an RNA stem-loop structure, the SECIS element in the 3 untranslated region of (UTR) selenoprotein mRNAs. Despite little sequence conservation, SECIS elements share the same overall secondary structure. Until recently, the lack of a significantly high number of selenoprotein mRNA sequences hampered the identification of other potential sequence conservation. In this work, the web-based tool SECISaln provides for the first time an extensive structure-based sequence alignment of SECIS elements resulting from the well-defined secondary structure of the SECIS RNA and the increased size of the eukaryotic selenoproteome. We have used SECISaln to improve our knowledge of SECIS secondary structure and to discover novel, conserved nucleotide positions and we believe it will be a useful tool for the selenoprotein and RNA scientific communities. SECISaln is freely available as a web-based tool at [Link]
[A]: What is the name of the stem loop present in the 3' end of genes encoding for selenoproteins?


[Q]: Nestin is a unique intermediate filament protein. While it is robustly expressed in developing brain, postnatal expression is limited to the brain's subventricular zone (SVZ) and endothelial cells. Reexpression occurs, however, under several pathological conditions, including injury and neoplasia. We hypothesized that nestin would be a sensitive marker of early neoplasia after transplacental exposure of rats to ethylnitrosourea (ENU). Rats of various ages were administered bromodeoxyuridine (BudR) before sacrifice, and brain sections were examined for proliferative cells and several immunohistochemical markers, including nestin. Additional rats were examined after a stab wound injury to assess the expression of two of these markers, GFAP and nestin, in reactive astrocytes. All ENU-induced brain tumors (n = 9) were classified as gliomas (astrocytomas or oligoastrocytomas) based on their histology and immunophenotype. Nestin expression was noted in all tumors examined and was present in tumor cells as well as endothelial cells. During tumor development, we consistently noted nestin-expressing cells bearing multiple processes distributed throughout brain parenchyma. Both single cells and multiple cell clusters were observed as early as postnatal day 30 in all ENU-exposed brains examined (n = 11). Such distinctive nestin-expressing cells were not seen in nestin-stained control brains or ENU-exposed brains stained for GFAP or vimentin, nor was such a cell seen in a stab wound model used to assess reactive astrocytosis. While the number of these clusters was highly variable among rats, their size increased between 30 and 90 days. The data suggest that these nestin-expressing cells represent an early stage of the neoplastic process. It remains to be determined whether these cells become apparent at 30 days of age due to "dedifferentiation" of a local resident astrocyte or astrocyte precursor cell or migration of a relatively undifferentiated precursor/stem cell from the SVZ.
[A]:
Which intermediate filament (IF) protein can be used as a non-specific marker of the neuronal precursor cells of the subventricular zone?