Transfusion medicine, or transfusiology, is the branch of medicine that is concerned with transfusion of blood and blood components. It encompasses issues of blood donation, immunohematology and other laboratory testing, transfusion practices, patient blood management, therapeutic apheresis, stem cell collections, cellular therapy, and coagulation. Laboratory management and understanding of state and federal regulations related to blood products are also a large part of the field. Transfusion Medicine is usually a branch of clinical pathology.