Mutations in SLC40A1, coding for Ferroportin, can lead to different autosomal dominant phenotypes: gain-of-function mutations (SLC40A1gf) are responsible for type 4 HH (formerly HH Type 4B) whose manifestations resemble those of HFE-HH, while the more frequent loss-of-function-mutations (SLC40A1lf) lead to Ferroportin disease (formerly HH Type 4A) often characterized by hyperferritinemia with normal TSAT and prevalent sinusoidal iron accumulation [1,6,7]. The gene discussed is SLC40A1; the disease is hemochromatosis type 4.