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: Globally, heterosexual intercourse is the primary route of HIV-1 (HIV) transmission. It follows that mechanisms that protect against HIV infection are likely operative at the genital mucosa. In HIV-resistant Kenyan sex workers who are highly exposed to HIV infection yet remain uninfected, protection correlates with HIV-specific immune responses and genetic factors. However, these factors do not entirely explain this model of natural immunity to HIV. We hypothesized that protection may be mediated by innate immune proteins in the genital tract of HIV-resistant sex workers.', 'The genital proteome of mucosal secretions from HIV-resistant women was examined using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry. Cervical lavage samples were collected from 315 HIV-resistant, HIV-uninfected and HIV-infected commercial sex workers.', 'Univariate analysis identified a 6 kDa biomarker of HIV resistance in genital secretions from these women. This protein was identified by tandem mass spectrometry as elafin and was found to be overexpressed in HIV-resistant women compared with HIV-uninfected (P = 0.001) and infected (P = 0.002) women. The elevated levels of elafin/trappin-2 in HIV-resistant women were confirmed using ELISA. The prospective association of elevated cervicovaginal elafin/trappin-2 levels with protection from HIV acquisition was then confirmed in an independent cohort of high-risk female sex workers.\Question: Does elevated elafin/trappin-2 in the female genital tract is associate with protection against HIV acquisition?
[EX A]: Using a unique proteomics approach in a large scale, cross-sectional cohort study, we identified elafin/trappin-2 as a novel innate immune factor, which is highly associated with resistance. This association was confirmed within an independent, prospective cohort study. Genital tract elafin/trappin-2 levels constitute a natural correlate of HIV protection in humans.

[EX Q]: Context: To clarify the pathways between household livestock and child growth by assessing the relationships between consumption of animal-source foods (ASF) and child growth and evaluating the household livestock correlates of child consumption of ASF.', 'We conducted a longitudinal cohort study of anthropometry and 3 d feeding recalls among children <5 years old between June 2014 and May 2015. In addition, we collected data on wealth, livestock ownership and livestock diseases in the same households. We used linear and negative binomial mixed models to evaluate the relationships between household livestock characteristics, reported consumption of ASF and child growth.', 'An 1800-household surveillance catchment area in Western Kenya within the structure of human and animal health surveillance systems.', 'Children (n 874) <5 years old.', 'Among children >6 months old, reported frequency of egg and milk consumption was associated with increased monthly height gain (for each additional report of consumption over 3 d: adjusted β (95 % CI)=0·010 (0·002, 0·019) cm/month and 0·008 (0·004, 0·013) cm/month, respectively). Poultry ownership was associated with higher reported frequency of egg, milk and chicken consumption (adjusted incidence rate ratio (95 % CI)=1·3 (1·2, 1·4), 1·4 (1·1, 1·6) and 1·3 (1·1, 1·4), respectively). Some livestock diseases were associated with lower reported frequency of ASF intake (livestock digestive diseases-adjusted incidence rate ratio (95 % CI)=0·89 (0·78, 1·00)).\Question: Is child height gain associated with consumption of animal-source foods in livestock-owning households in Western Kenya?
[EX A]: Child height gain was associated with milk and egg consumption in this cohort. ASF consumption was related to both household livestock ownership and animal health.

[EX Q]: Context: The aim of this study was to evaluate the expression of vascular endothelial growth factor (VEGF) in response to retinoic acid (RA) in human retinal pigment epithelial cells.', 'Expression of VEGF in human ARPE-19 cells was determined by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). mRNA stability was assessed after the administration of actinomycin D. The induction of the VEGF gene by various RAs was also determined by semiquantitative RT-PCR.', 'All-trans retinoic acid (atRA) time-dependently increased VEGF mRNA levels. The effect of atRA was dose-dependent in a range between 10(-7) M and 10(-6) M. Treatment with actinomycin D revealed that atRA induces the VEGF gene at the transcriptional level. Of the various RAs tested, atRA was the most potent inducer of the VEGF gene.\Question: Does retinoic acid induce VEGF gene expression in human retinal pigment epithelial cells ( ARPE-19 )?
[EX A]:
We demonstrated that atRA stimulates the induction of the VEGF gene in ARPE-19 cells, suggesting a novel pathway for the development of age-related macular degeneration.