F5 and hemophilia: According to data from the World Federation of Hemophilia and the European Network of Rare Bleeding Disorders, the most common deficiencies among the entire affected population were FVII (39%) and FXI (26%), fibrinogen, FV, and FX (8-9%), FXIII (6%), and combined FV and FVIII (3%); FII deficiency (prevalence, 1%) was the rarest disorder [3].