Advances in diagnostic techniques, such as noncontrast Magnetic Resonance Direct Thrombus Imaging (MRDTI) and serial ultrasonography, have revealed that 40% of UEDVT cases are associated with malignancy, while 12–42% are linked to underlying coagulopathies, such as factor V Leiden or protein S deficiency [5, 6, 9]. Here, PROS1 is linked to blood coagulation disease.