Supporting TMPRSS6’s crucial role in iron regulation, it was discovered that mutations in the TMPRSS6 gene can impair TMPRSS6 functionalities such as its autoactivation [7] which resulted in sustained BMP-SMAD signaling, elevated production of hepcidin, low plasma iron levels and thus iron-refractory iron deficiency anemia [8]. The gene discussed is TMPRSS6; the disease is anemia.