In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: Strontium ranelate reduces fracture risk in postmenopausal women with osteoporosis. Evidence from non-clinical studies and analyses of bone markers in phase III trials indicate that this is due to an increase in osteoblast formation and a decrease of osteoclastic resorption. The aim of this work was to investigate, in human cells, the mechanisms by which strontium ranelate is able to influence the activities of osteoblasts and osteoclasts.', 'Human primary osteoblasts were used to examine effects of strontium ranelate on replication (thymidine incorporation), differentiation (Runx2 and alkaline phosphatase) and cell survival (cell counts and caspase activity). Osteoprotegerin (OPG) was measured by quantitative reverse transcription PCR (qRT-PCR) and elisa and receptor activator of NFkappaB ligand (RANKL) by qRT-PCR and Western blot. As strontium ranelate has been proposed as an agonist of the calcium-sensing receptor (CaSR), the involvement of CaSR in the effects of strontium ranelate on OPG and RANKL expression, and cell replication was examined using siRNA.', 'Strontium ranelate increased mRNA and protein levels of OPG and suppressed those of RANKL. Strontium ranelate also stimulated osteoblast replication and differentiation and increased cell survival under stress. Knocking down CaSR suppressed strontium ranelate-induced stimulation of OPG mRNA, reduction of RANKL mRNA, and increase in replication, indicating the involvement of CaSR in these responses.\Question: Do osteoblasts play key roles in the mechanisms of action of strontium ranelate?
[EX A]: Our results demonstrate that osteoblasts play a key role in the mechanism of action of the anti-fracture agent, strontium ranelate by mediating both its anabolic and anti-resorptive actions, at least in part, via activation of CaSR.

[EX Q]: Context: Evidence of attack-related cognitive dysfunction in migraine is growing. Controversy exists on whether cognitive dysfunction, mainly executive, may persist between attacks. Measuring the impact of cognitive function is gaining importance in clinical and research settings in migraine.', 'To compare the performance of interictal migraine patients to controls in an assembled neuropsychological battery focused on executive functions and to study the practice effect of its repeated applications.', 'Assembly of the battery that was then applied twice within 6\xa0weeks to interictal migraineurs and matched healthy controls.', 'Migraine patients (n\xa0=\xa024) and controls (n\xa0=\xa024) had similar performance in both applications of the battery. There was a slight practice effect between the first and second evaluation, significant in Stroop Interference test (P\xa0=\xa00.002, multiplicity corrected); a meaningful score change was determined for each raw test scores.\Question: Is sequential brief neuropsychological evaluation of migraineurs identical to controls?
[EX A]: Interictal migraineurs and controls performance is identical in a brief cognitive battery focused on executive functions. Repeated applications produced a practice effect that was quantified.

[EX Q]: Context: This study investigated whether cholesterol levels influence the expression and function of drug transporters and whether statin treatments could alter this by reducing plasma low-density lipoprotein cholesterol levels.', 'The mRNA expression and function of OATP1B1, ABCB1 and ABCG2 were assessed in peripheral blood mononuclear cells (PBMCs) of healthy subjects and from patients with familial hypercholesterolemia (FH) before and after statin treatment by real-time PCR and flow cytometric assay, respectively. The effects of statin exposure and cholesterol depletion in PBMCs and in cell lines were assessed.', 'ABCG2 expression and activity in PBMCs in patients with FH were 2-fold and 26-fold higher, respectively, than those of the healthy subjects (p < 0.001 for both). Statin treatment decreased ABCG2 expression and function in patients with FH. Depletion of cholesterol ex vivo reduced ABCG2 expression in PBMCs and reduced ABCG2 activity in liver and colon cells.\Question: Are expression and activity of ABCG2 , but not ABCB1 or OATP1B1 , associated with cholesterol levels : evidence from in vitro and in vivo experiments?
[EX A]:
This study suggested that statins may downregulate ABCG2 expression and function through reducing low-density lipoprotein cholesterol levels.