Given a passage with a context and an answer, 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.

[Q]: Context: Current staging for renal cancer (RC) does not directly rely on tumor size. We examined the increment in accuracy related to inclusion of pathologically determined tumor size in prediction of nodal metastases (N+), distant metastases (M+), and cancer-specific survival (CSS).', 'Partial or radical nephrectomy was performed in 2245 patients with clear cell histology. Pathologic stages were T1a in 566, T1b in 490, T2 in 303, T3 in 831, and T4 in 55 patients. Tumor size was 0.5-25 cm (mean, 6.8). Multivariate models relied on 1997 and 2002 TNM variables and addressed N+, M+ disease, and CCS. Their accuracy was compared according to either the presence or absence of tumor size.', 'In all univariate and multivariate models, tumor size was a statistically significant predictor of all outcomes (p< or =0.001). In all multivariate models, tumor size added between 3.7% and 0.8% to predictive accuracy of either 1997 or 2002 TNM categories.
Answer: Tumor size represents a highly significant, multivariate, and informative predictor of RC outcomes and may warrant inclusion in future TNM revisions.
[A]: Does tumor size improve the accuracy of TNM predictions in patients with renal cancer?


[Q]: Context: Pandemic strains of HIV-1 (group M) encode a total of nine structural (gag, pol, env), regulatory (rev, tat) and accessory (vif, vpr, vpu, nef) genes. However, some subtype A and C viruses exhibit an unusual gene arrangement in which the first exon of rev (rev1) and the vpu gene are placed in the same open reading frame. Although this rev1-vpu gene fusion is present in a considerable fraction of HIV-1 strains, its functional significance is unknown.', 'Examining infectious molecular clones (IMCs) of HIV-1 that encode the rev1-vpu polymorphism, we show that a fusion protein is expressed in infected cells. Due to the splicing pattern of viral mRNA, however, these same IMCs also express a regular Vpu protein, which is produced at much higher levels. To investigate the function of the fusion gene, we characterized isogenic IMC pairs differing only in their ability to express a Rev1-Vpu protein. Analysis in transfected HEK293T and infected CD4+ T cells showed that all of these viruses were equally active in known Vpu functions, such as down-modulation of CD4 or counteraction of tetherin. Furthermore, the polymorphism did not affect Vpu-mediated inhibition of NF-кB activation or Rev-dependent nuclear export of incompletely spliced viral mRNAs. There was also no evidence for enhanced replication of Rev1-Vpu expressing viruses in primary PBMCs or ex vivo infected human lymphoid tissues. Finally, the frequency of HIV-1 quasispecies members that encoded a rev1-vpu fusion gene did not change in HIV-1 infected individuals over time.
Answer: Expression of a rev1-vpu fusion gene does not affect regular Rev and Vpu functions or alter HIV-1 replication in primary target cells. Since there is no evidence for increased replication fitness of rev1-vpu encoding viruses, this polymorphism likely emerged in the context of other mutations within and/or outside the rev1-vpu intergenic region, and may have a neutral phenotype.
[A]: Does a Naturally Occurring rev1-vpu Fusion Gene Confer a Fitness Advantage to HIV-1?


[Q]: Context: Deep erythema and inflammation after re-epithelialization of superficial wounds is a sign of scar formation. Corticosteroids may prevent scarring by suppression of inflammation and fibroblast activity. Tretinoin may increase the efficacy of corticosteroids in this setting.', 'To evaluate the efficacy of corticosteroids plus tretinoin for prevention of scars after superficial wounds.', 'In a retrospective study of patients with superficial partial thickness thermal skin burn, we compared the patients who received clobetasol plus tretinoin after re-epithelialization with patients who did not receive any medication. Clobetasol propionate 0.05% ointment was used twice daily with overnight occlusive dressing in conjunction with twice weekly topical tretinoin 0.05% cream.', 'Among 43 patients who had light pink or no erythema after re-epithelialization and consequently did not receive clobetasol\u2009+\u2009tretinoin, no scar was developed. Among patients who had deep erythema after re-epithelialization, rate of scar formation was significantly higher in 14 patients who did not receive clobetasol\u2009+\u2009tretinoin than in 21 patients who received clobetasol\u2009+\u2009tretinoin (64% and 19%, respectively; p\u2009=\u20090.01).
Answer: Clobetasol + tretinoin can significantly decrease the incidence of scar formation in patients with inflammation after re-epithelialization of superficial wounds.
[A]:
Is topical clobetasol in conjunction with topical tretinoin effective in preventing scar formation after superficial partial-thickness burn ulcers of the skin : A retrospective study?