CCL2 and rheumatoid arthritis: The hub targets of QHSSD in RA therapy are as follows: IL-6, TP53, VEGFA, JUN, TNF, MAPK1, MAPK8, EGF, PTGS2, MAPK3, EGFR, ESR1, IL-1B, CAT, CCL2, MAPK14, MMP2, and NOS3.