MMP3 and rheumatic heart disease: MMP-3 also has a plethora of functions, such as acting as a common inflammatory factor that promotes inflammation, and it plays a complicated role in the nervous system, a few of which are peripheral nerve injuries directly related to the oversecretion of MMP-3 [37] MMP-3 gene polymorphism is also found to have a direct relation with increased occurrence and development of cardiovascular diseases such as rheumatic heart disease and atherosclerosis [38,39].