Several studies have been conducted to study the role of matriptase-2, by crossing Tmprss6 knockout mice with several iron overload mouse models, including the generations of Hjv/Tmprss6, Bmp6/Tmprss6, Hfe/Tmprss6, and Tfr2/Tmprss6 double mutant mice (Truksa et al., 2009; Finberg et al., 2011; Lenoir et al., 2011; Lee et al., 2012). Here, TMPRSS6 is linked to Tangier disease.