tPA also known as PLAT is a secreted serine protease that converts the proenzyme plasminogen to plasmin, a fibrinolytic enzyme. tPA plays a crucial role in the fibrinolytic system, primarily facilitating the breakdown of fibrin in blood clots, which is essential for maintaining normal blood flow and preventing excessive clot formation. tPA is secreted by endothelial cells and is found in the bloodstream, where tPA acts to convert plasminogen into plasmin, the active enzyme responsible for degrading fibrin. The regulation of tPA is vital, as an imbalance can lead to pathological conditions such as thrombosis or hemorrhage. Additionally, tPA interacts with various proteins, including plasminogen activator inhibitor-1 (PAI-1), which modulates tPA activity and stability.