MMP3 and rheumatoid arthritis: A clinical study (13) has shown that RES can significantly improve the disease status of patients with RA and significantly reduce the serum levels of related biochemical indicators, namely, C-reactive protein, erythrocyte sedimentation rate, carboxylated osteocalcin, matrix metalloproteinase-3 (MMP-3) tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6).