SLC40A1 and obesity due to melanocortin 4 receptor deficiency: Elevated SF without elevated TS is common in patients with obesity [15], metabolic syndrome [16], diabetes [17], non-alcoholic fatty liver disease [18, 19], inflammatory disorders [16], malignancies [20–22], "classic" ferroportin hemochromatosis due to deleterious SLC40A1 alleles [16], hereditary hyperferritinemia-cataract syndrome [16], and benign autosomal dominant hyperferritinemia [23].