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

[EX Q]: The calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that plays an essential role in maintaining calcium homeostasis. In the present study, we analyzed the CaSR gene in a Korean family with familial hypocalciuric hypercalcemia (FHH). Genetic studies were performed by direct sequence analysis of the CaSR gene in genomic DNA obtained from peripheral leukocytes. A novel heterozygous G to T substitution at nucleotide position 1711 in exon 6, resulting in the G571W mutation, was identified in the CaSR gene in a 26-year-old female with asymptomatic hypercalcemia, a low calcium/creatinine clearance ratio, and normal intact parathyroid hormone. To study CaSR expression, the mutation was introduced by site-directed mutagenesis into a wild-type (WT) CaSR-expressing pCR3.1 vector, and COS-7 cells were transfected with either the WT or mutant CaSR-containing vector. Transfected cells loaded with Fura-2/AM, a fluorescent indicator of Ca
[EX A]: What is the function of calcium-sensing receptor (CaSR)?

[EX Q]: MicroRNAs (miRNAs) constitute a large family of noncoding RNAs that function as guide molecules in diverse gene silencing pathways. Current efforts are focused on the regulatory function of miRNAs, while little is known about how these unusual genes themselves are regulated. Here we present the first direct evidence that miRNA genes are transcribed by RNA polymerase II (pol II). The primary miRNA transcripts (pri-miRNAs) contain cap structures as well as poly(A) tails, which are the unique properties of class II gene transcripts. The treatment of human cells with alpha-amanitin decreased the level of pri-miRNAs at a concentration that selectively inhibits pol II activity. Furthermore, chromatin immunoprecipitation analyses show that pol II is physically associated with a miRNA promoter. We also describe, for the first time, the detailed structure of a miRNA gene by determining the promoter and the terminator of mir-23a approximately 27a approximately 24-2. These data indicate that pol II is the main, if not the only, RNA polymerase for miRNA gene transcription. Our study offers a basis for understanding the structure and regulation of miRNA genes.
[EX A]: Which polymerase transcribes pri-miRNAs?

[EX Q]: To evaluate the results of facial nerve (FN) grafting using great auricular cable graft and fibrin glue without suturing to palliate FN disruption after removal of large cerebellopontine angle (CPA) vestibular schwannoma (VS) or facial nerve schwannoma (FNS). To assess whether tumor size and origin influenced the results. Retrospective review of all patients having undergone removal of FNS/VS and needing intraoperative FN repair between 2001 and 2011. FN was rehabilitated using great auricular nerve cable graft and fibrin glue (Tisseal) without stitching suture. All data recorded were reviewed to access age, sex, tumor type, and tumor size according to the Koos classification and presenting symptoms. FN function was evaluated preoperatively and at 18 months using the House-Brackmann (HB) grading system. Among the 595 patients operated for CPA schwannomas in this period, 15 patients (2.5%) underwent FN repair, including 7 cases of FNS and 8 cases of VS. Tumor removal was total in all cases. FN recovery was HB3 in 13 cases (86.7%) and HB4 in 2. The mean time to the first clinical signs of facial reinnervation was 10 months (6-12 mo). No significant relation was found between postoperative facial function and tumor size or type, even if all cases of preoperative FP were noted in FNS. Immediate FN reconstruction with fibrin glue-aided greater auricular nerve graft can effectively restore FN function with excellent outcomes. The results seem better than those observed by other authors using sutured grafts or delayed hypoglossal-facial nerve anastomosis.
[EX A]:
Which disease can be categorized using the Koos grading system?