Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Example Input: To determine whether the number and location of positive surgical margins (PSMs) in radical prostatectomy (RP) surgical specimens affect biochemical recurrence (BCR) rates.', 'The locations of PSMs were recorded for 1308 consecutive men who underwent RP between October 2000 and December 2006. BCR was defined as three consecutive prostate-specific antigen (PSA) level rises with the peak level >or=0.15 ng/mL. Multivariate regression analyses were used to identify preoperative predictors of PSMs and BCR. The estimated 5-year risk of BCR was calculated using the Kaplan-Meier method.', 'In all, 128 (9.8%) men had one or more PSMs. The mean body mass index, mean preoperative serum PSA level, the distributions of clinical stage and biopsy Gleason scores, and the presence or absence of biopsy perineural invasion were significantly different between men with or with no PSMs. In multivariate analysis, baseline serum PSA level, Gleason score and perineural invasion were independent preoperative predictors of PSMs. The 5-year actuarial BCR rates were dependent on the site of the PSM (P = 0.035) and not the number of PSMs (P = 0.18). The rank order of estimated 5-year BCR rates according to the site of PSMs were base > anterior > posterolateral > apex approximately posterior.
Example Output: Does site of positive surgical margins influence biochemical recurrence after radical prostatectomy?

Example Input: A defect in retinal pigment epithelial (RPE) cells may cause dysfunction of the neural retina, so rapid recovery of differentiated RPE cells is required after RPE injury. We investigated the effect of hepatocyte growth factor (HGF) on wound healing in RPE cells.', 'Confluent monolayers of bovine RPE cells were denuded, and the cells were allowed to recover in the presence or absence of HGF. The effect of HGF on RPE cell proliferation was evaluated by a 3-(4;5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetraz olium assay. In a migration assay, mitomycin C was used to inhibit proliferation, and the number of migrated cells was counted. The signaling pathways involved were examined using inhibitors of mitogen-activated protein kinase (MAPK), phosphatidylinositol-3 (PI3) kinase and protein kinase C pathways.', 'At 80 ng/mL, HGF stimulated the wound closure of RPE monolayers and rendered the restituted cells more epithelioid in shape. HGF at 10 ng/mL stimulated RPE cell migration the most, whereas 80 ng/mL of HGF inhibited migration, but stimulated proliferation the most. In particular, PI3 kinase and MAPK inhibitor inhibited PRE cell migration and proliferation, respectively.
Example Output: Does hepatocyte growth factor stimulate proliferation and migration during wound healing of retinal pigment epithelial cells in vitro?

Example Input: CXCL4 is a platelet chemokine released at micromolar concentrations upon platelet activation. CXCL4 has been shown to promote atherogenesis by various mechanisms. However, data on CXCL4 plasma levels in patients with coronary artery disease are largely inconclusive. Computed coronary artery angiography (CCTA) represents an excellent tool to quantify and characterize coronary atherosclerotic plaques. We hypothesized that increased CXCL4 plasma levels may be associated with features of plaque instability resulting in adverse cardiovascular events. Specifically, we sought to determine whether CXCL4 levels are correlated with specific features of coronary artery disease including (1) plaque volume, (2) calcium score, (3) degree of stenosis, or (4) vascular remodeling.', 'CXCL4 plasma levels were measured by ELISA in 217 patients undergoing CCTA for suspected CAD (mean age 64.2 9.4 years, 107 (49.3%) male). Mean CXCL4 plasma levels were 12.5 4.6 ng/mL. There was no significant correlation between CXCL4 levels and any clinical or demographic parameters including cardiovascular risk factors. CXCL4 plasma levels did not differ between patient with or without coronary artery disease (CAD: 12.5 4.5 ng/ml, no CAD: 12.5 4.8 ng/ml). Neither univariate nor multivariate analysis showed an association between CXCL4 levels and plaque volume, total calcium score, degree of stenosis, or vascular remodeling. Subgroup analysis of patients with CAD as confirmed by CCTA did not show any association of CXCL4 levels with the extent of CAD.
Example Output:
Are cXCL4 Plasma Levels Associated with the Extent of Coronary Artery Disease or with Coronary Plaque Morphology?