Cation-independent M6PR (IGF2R

This gene encodes a receptor for both insulin-like growth factor 2 and mannose 6-phosphate. The binding sites for each ligand are located on different segments of the protein. This receptor has various functions, including in the intracellular trafficking of lysosomal enzymes, the activation of transforming growth factor beta, and the degradation of insulin-like growth factor 2. Mutation or loss of heterozygosity of this gene has been association with risk of hepatocellular carcinoma. The orthologous mouse gene is imprinted and shows exclusive expression from the maternal allele; however, imprinting of the human gene may be polymorphic, as only a minority of individuals showed biased expression from the maternal allele (PMID:8267611).