F9 and hemophilia B: Hemophilia can be categorized into hemophilia A (Factor VIII deficiency, OMIM_306700), resulting from coagulation factor VIII (F8) variants; hemophilia B (Factor IX deficiency, OMIM_306900), caused by coagulation factor IX (F9) variants; and Factor XI deficiency (OMIM_612416), associated with coagulation factor XI (F11) variants (2–4).