CFH and hyperinsulinemic hypoglycemia, familial, 4: Recently, an additional aspect of renal pathogenesis was elucidated through the generation of mice with Cfh and properdin deficiency.123, 124 Because properdin prolongs the cleaving activity of the AP C3 convertase, it was hypothesized that genetic deficiency of properdin (as a positive regulator of the AP) would ameliorate the renal phenotype of Cfh deficiency.