Promotes absorption of the essential vitamin cobalamin (Cbl) in the ileum. After interaction with CUBN, the CBLIF-cobalamin complex is internalized via receptor-mediated endocytosis (By similarity). Interacts with CUBN (via CUB domains). Gastric mucosa. The N-terminus is blocked. Belongs to the eukaryotic cobalamin transport proteins family. Extended N-terminus. Extended N-terminus.