Among the top 10 DEPs most significantly associated with Δ mGFR, secreted frizzled-related protein 4 (SFRP4), PDGFR α (PDGFRA), TNF-inducible gene 6 protein (TSG-6), extracellular superoxide dismutase 3 (SOD3), CMRF35-like molecule 9 (CLM9), IGF-II: Proform, interleukin 11 receptor subunit α (IL-11 RA), vascular endothelial growth factor D (VEGF-D), and IGF-binding protein 3 (IGFBP3), were positively associated with Δ mGFR, while PSA was negatively associated with Δ mGFR (P < 0.01). The gene discussed is SFRP4; the disease is rheumatoid arthritis.