Previous research has shown that a family of genes, proteins and enzymes called the uPA system (for urokinase plasminogen activator) plays an active role in different facets of cancer's biology, including tumor cell invasion, the spread of metastases, and the growth of a primary tumor.<img src="http://feeds.feedburner.com/~r/sciencedaily/~4/WQUqvai1kD8" height="1" width="1"/>
