MMP9 and rheumatoid arthritis: RA associated joint destruction is accompanied by overexpression of several including matrix metalloproteinases (MMPs), particularly MMP-3 and MMP-9, which are considered as valid biomarkers of disease progression and joint destruction cytokines IL-23, IL-17, and chemokine RANKL (Bian et al., 2023; Ju et al., 2008; Adamopoulos et al., 2011).