PTH and rheumatoid arthritis: The results of the KEGG enrichment analysis revealed that co-expressed genes were mostly related to oxytocin signaling pathway, rheumatoid arthritis, epithelial cell signaling in Helicobacter pylori infection, human papillomavirus infection, Vibrio cholerae infection, parathyroid hormone synthesis, secretion and action, and amoebiasis (Figure 4B; Supplementary Table S2).