Professor Leclercq and his team studied certain mechanisms at the basis of the multiplication of cancer cells and metastasis (or metastases). They study, in particular, a protein that is produced by tumors (neoplasms) and which can interfere with the proper functioning of the natural defense mechanism of the body. Tumor cells have developed several mechanisms that promote cell proliferation and metastases to other organs or to avoid being rejected by the immune system of the patient. Urokinase (also referred to as urokinase-type plasminogen activator or uPA) is a protein that is produced by aggressive tumors. The cancer cells use to leave their original tumor and migrate to other organs, causing the tumor treatment more difficult. We have recently demonstrated that uPA also has another function: it can namely also suppress the activity of immune cells. This project will investigate whether uPA production leads effectively by tumor cells to suppress the elimination of these tumor cells by immune cells. If this is the case, this mechanism as a target for new anti-cancer treatment.