SMAD7 and rheumatoid arthritis: The hub genes with altered expression following PSPA treatment include the upregulated H3f3c, Pparg, Casp3, Hspa5, and Cryab, and the downregulated Cd34, Ccnd1, and Smad7. Among these hub genes, Pparg plays a pivotal role in the onset and progression of epigenetic disorders and arthritis, elucidating crucial regulatory pathways and gene targets associated with epigenetic DNA methylation abnormalities in RA (56).