 This study integrated three gene expression profile datasets and one methylation profile dataset to identify potential essential candidate genes and pathways involved in rheumatoid arthritis, i.a. Differentially expressed genes, DEGs, and differentially methylated genes, DMGs, were identified using a programming software, and functional annotation and protein-protein interaction network analysis were performed. Enrichment analysis revealed that DEGs mainly involved immune response and participated in the cytokine-cytokine receptor interaction signal pathway. Cross-analysis of DEGs and DMGs identified food genes that exhibited differential expression and methylation in i, which could be used as targets for further research on i. This article was authored by Di Zhong, Zhao Fangli, Rong Qiang Zhong, and others.