F8 and hyperinsulinemic hypoglycemia, familial, 4: Among patients with FVIII deficiency, inhibitor development was most common in the recombinant subgroup (14/43; 32.6%), which was followed by the plasma-derived subgroup (19/59; 32.2%), the group with multiple products (6/22; 27.3%), and the fresh frozen plasma group (4/18; 22.2%).