The Plasminogen Activator System (PAS) is a multifunctional protease system known to possess mitogenic, chemotactic, adhesive and migratory properties. Consequently, it plays an essential role in the process of tumor cell growth and metastasis. Tissue plasminogen activator (t PA) is a member of the serine protease family that plays a pivotal role in the homeostasis of blood coagulation/fibrinolysis and matrix regulation. This book discusses the use of PAS in cancer treatment; its role in chronic kidney disease; the genetic factors, functions, and clinical applications; obesity in adolescents; and the mutual interactions and potential combinatory implications in oncotherapies.