The function of ENSG00000166126 (AMN, amnion associated transmembrane protein) is as follows. Membrane-bound component of the endocytic receptor formed by AMN and CUBN (PubMed:14576052, PubMed:29402915, PubMed:30523278). Required for normal CUBN glycosylation and trafficking to the cell surface (PubMed:14576052, PubMed:29402915). The complex formed by AMN and CUBN is required for efficient absorption of vitamin B12 (PubMed:12590260, PubMed:14576052, PubMed:26040326). Required for normal CUBN-mediated protein transport in the kidney (Probable). {ECO:0000269|PubMed:12590260, ECO:0000269|PubMed:14576052, ECO:0000269|PubMed:26040326, ECO:0000269|PubMed:29402915, ECO:0000269|PubMed:30523278, ECO:0000305|PubMed:22631584, ECO:0000305|PubMed:26040326}.