HFE, also known as HLA-H, belongs to the MHC class I family. This protein contains 1 Ig-like C1-type (immunoglobulin-like) domain. HFE is a membrane protein that is similar to MHC class I-type proteins and associates with beta-2 microglobulin (beta2M). It is thought that this protein functions to regulate iron absorption by regulating the interaction of the transferrin receptor (TFR) with transferrin. It binds to transferrin receptor (TFR) and reduces its affinity for iron-loaded transferrin. Recombinant human HFE protein, fused to His-tag at N-terminus, was expressed in E.coli.