The PLG/plasmin system is primarily involved in the degradation of fibrin but also is a key participant in other proteolytic migratory cellular functions, including tissue repair, extracellular matrix degradation, angiogenesis, tumor invasion, inflammatory cell migration, complement protein interactions, and in maintaining healthy body mucosal surfaces by removing fibrin and misfolded proteins from extravascular tissues (22–27). The gene discussed is PLG; the disease is neoplasm.