MMP13 and rheumatoid arthritis: By comparing FLS from healthy individuals to FLS-RA it has been demonstrated that statistically significant differences can occur in heat-shock protein family A members, matrix metalloproteinase 1 (MMP1), matrix metalloproteinase 13 (MMP13) and tumor necrosis factor ligand superfamily member 10 (TNFSF10) genes [111,112,113,114].