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Figure legend
Figure 1. Results of the association between methylation and mRNA levels of ERAP1 and AS. A) The odds ratio (ORs) and 95% confidence intervals (CIs) of the methylation 31 CpG loci in ERAP1_1 and ERAP1_2 islands, and six loci in ERAP1_2 island were significantly associated with increased risk of AS. B) The methylation level of ERAP1_1 island was significantly increased in AS patients. C) The methylation level of ERAP1_2 island was significantly increased in AS patients. D) The ROC curves of the methylation levels of ERAP1_1 island, ERAP1_2 island and the combination of all the significantly differential methylated CpG loci. E) The ERAP1 relative expression level was significantly decreased in AS patiens.