Protein S is a vitamin K-dependent anticoagulant protein. The mechanism of protein S has been one of the least understood amongst the vitamin K-dependent coagulation proteins but it has a central role in the regulation of coagulation1. A deficiency of protein S predisposes to recurrent venous thromboembolism and fetal loss23.
This is a companion discussion topic for the original article at https://patient.info/doctor/haematology/protein-s-deficiency