Matrix metalloproteinases (MMPs) are proteolytic enzymes which degrade extracellular matrix and basement membrane. There is much evidence that their increased expression is correlated with tumor aggressiveness in various carcinomas. Tissue inhibitor of metalloproteinases (TIMPs) are the specific inhibitors of MMPs. MMPs and TIMPs are considered to play an important role in carcinoma invasion and metastasis. We hypothesized that MMPs and TIMPs also play an important role in thymoma.
