It is worth noticing that the management of FXI deficiency can be quite challenging for a number of reasons: the bleeding phenotype is unpredictable because is not dependent on FXI levels, large amounts of FFP are required for adequate hemostasis, FXI concentrate is not available in all regions, and existing replacement therapies have a significant thrombotic risk [21]. This evidence concerns the gene F11 and hyperinsulinemic hypoglycemia, familial, 4.