MMP‐3 is a member of MMP family, which is involved in the breakdown of extracellular matrix proteins and tissue remodelling in normal physiological processes or disease processes, such as arthritis, and tumour metastasis.28, 29 TIMP‐3 is member of tissue inhibitor of metalloproteinases family, which is a group of peptidases involved in degradation of the ECM. The gene discussed is TIMP3; the disease is Arthritis.