Acts as an importer of heme. Also acts as a transporter for a calcium-chelator complex, important for growth and calcium metabolism. Expressed in non-hematopoietic tissues, with relative abundant expression in brain, placenta, lung, liver and kidney. Also expressed in hematopoietic tissues (fetal liver, spleen, lymph node, thymus, leukocytes and bone marrow). Found in acidophil cells of the pituitary that secrete growth hormone and prolactin. The disease is caused by variants affecting the gene represented in this entry. Belongs to the major facilitator superfamily. Feline leukemia virus subgroup C receptor (TC 2.A.1.28.1) family.