Ences of endometrial cancer [18]. However, no statistically significant associations were found between XbaI (A.G) Homatropine methobromide polymorphism and endometrial cancer risk. The findings from this meta-analysis were consistent with the previous meta-analysis conducted by Wang et al, suggesting PvuII may be linked to the development of endometrial cancer. In addition to the previous meta-analysis, we also found a significant association between rs3020314 (C.T) polymorphism and an increased risk of endometrial cancer development, while the rs2234670 (S/L) polymorphism might decrease the risk of endometrial cancer development. Nevertheless, Codon 325 (C.G), Codon 243 (C.T), VNTR (S/L) and rs2046210 (G.A) polymorphisms showed no associations with the risk of endometrial cancer. These findings 23977191 are consistent with the previous hypothesis that variability in the ESR1 gene may alter the risk of developing endometrial cancer, suggesting that they may be useful as biomarkers in predicting an individual’s genetic susceptibility to endometrial cancer. Similar to other meta-analyses, our study also bears some limitations and shortages. First, the purchase ZK 36374 sample size is still relatively small and may not provide sufficient statistical power to estimate the correlations between ESR1 gene polymorphisms and endometrial cancer risk. Second, in this meta-analysis, potential sources of heterogeneity could include many other factors, such as age 
and sex structure, characteristics of healthy control, pre- and postmenopause, etc. Third, as a type of a retrospective study, a metaanalysis may encounter recall or selection bias, possibly influencing the reliability of our study results. Furthermore, in this metaanalysis, there is a significant difference in numbers between cancer cases and healthy controls, which may be one source of heterogeneity and may have some unfavorable effects on the reliability of our results. Finally, our lack of access to the original data from the studies limited further evaluation of potential interactions such as gene-environment and gene-gene interactions. In spite of these limitations, however, our present meta-analysis includes the largest number of eligible studies relevant to the relationship between ESR1 polymorphisms and endometrial cancer risk reported to date. In conclusion, our meta-analysis suggests that PvuII (C.T) and rs3020314 (C.T) polymorphisms may be risk factors in endometrial cancer development, especially among Caucasian populations. These relationships will promise us a functional profiling of ESR1 gene and an understanding of the biological processes associated with endometrial cancer development and progression. It may also be further utilized as a diagnostic tool, as well as, an accurate determination of endocrine therapeutic strategies in endometrial cancer. However, further studies are still needed in order 
to validate the associations between polymorphisms in ESR1 and endometrial cancer.Supporting InformationSupplement S1 PRISMA Checklist.ESR1 Polymorphisms and Endometrial Cancer Risk(DOC)Supplement S2 The modified STROBE quality score(ZIP)systems. (DOC) The genotype distributions of ESR1 polymorphism in case and control groups. (XLS)Supplement S3 Supplement S4 Forest plot of ORs by random effects model for all eight polymorphisms of ESR1 gene and endometrial cancer risk under five genetic models: the allele model (A), the dominant model (B), the recessive model (C), the homozygous model (D), and the heterozygous model (E).Acknow.Ences of endometrial cancer [18]. However, no statistically significant associations were found between XbaI (A.G) polymorphism and endometrial cancer risk. The findings from this meta-analysis were consistent with the previous meta-analysis conducted by Wang et al, suggesting PvuII may be linked to the development of endometrial cancer. In addition to the previous meta-analysis, we also found a significant association between rs3020314 (C.T) polymorphism and an increased risk of endometrial cancer development, while the rs2234670 (S/L) polymorphism might decrease the risk of endometrial cancer development. Nevertheless, Codon 325 (C.G), Codon 243 (C.T), VNTR (S/L) and rs2046210 (G.A) polymorphisms showed no associations with the risk of endometrial cancer. These findings 23977191 are consistent with the previous hypothesis that variability in the ESR1 gene may alter the risk of developing endometrial cancer, suggesting that they may be useful as biomarkers in predicting an individual’s genetic susceptibility to endometrial cancer. Similar to other meta-analyses, our study also bears some limitations and shortages. First, the sample size is still relatively small and may not provide sufficient statistical power to estimate the correlations between ESR1 gene polymorphisms and endometrial cancer risk. Second, in this meta-analysis, potential sources of heterogeneity could include many other factors, such as age and sex structure, characteristics of healthy control, pre- and postmenopause, etc. Third, as a type of a retrospective study, a metaanalysis may encounter recall or selection bias, possibly influencing the reliability of our study results. Furthermore, in this metaanalysis, there is a significant difference in numbers between cancer cases and healthy controls, which may be one source of heterogeneity and may have some unfavorable effects on the reliability of our results. Finally, our lack of access to the original data from the studies limited further evaluation of potential interactions such as gene-environment and gene-gene interactions. In spite of these limitations, however, our present meta-analysis includes the largest number of eligible studies relevant to the relationship between ESR1 polymorphisms and endometrial cancer risk reported to date. In conclusion, our meta-analysis suggests that PvuII (C.T) and rs3020314 (C.T) polymorphisms may be risk factors in endometrial cancer development, especially among Caucasian populations. These relationships will promise us a functional profiling of ESR1 gene and an understanding of the biological processes associated with endometrial cancer development and progression. It may also be further utilized as a diagnostic tool, as well as, an accurate determination of endocrine therapeutic strategies in endometrial cancer. However, further studies are still needed in order to validate the associations between polymorphisms in ESR1 and endometrial cancer.Supporting InformationSupplement S1 PRISMA Checklist.ESR1 Polymorphisms and Endometrial Cancer Risk(DOC)Supplement S2 The modified STROBE quality score(ZIP)systems. (DOC) The genotype distributions of ESR1 polymorphism in case and control groups. (XLS)Supplement S3 Supplement S4 Forest plot of ORs by random effects model for all eight polymorphisms of ESR1 gene and endometrial cancer risk under five genetic models: the allele model (A), the dominant model (B), the recessive model (C), the homozygous model (D), and the heterozygous model (E).Acknow.
