KEGG enrichment analysis showed that the genes of RA versus NC samples in modules 1 to 2 and OA versus NC samples were mainly associated with “melanoma,” “neuroactive ligand-receptor interaction,” “Rap1 signaling pathway,” “Wnt singaling pathway,” and “MAPK signaling pathway.” Furthermore, the DEGs of RA versus OA were significantly clustered in “chemokine signaling pathway” and “Jak-STAT signaling pathway.” Here, SOAT1 is linked to rheumatoid arthritis.