RBP2 is an abundant protein present in the smallintestinal epithelium. It is thought to participate in the uptakeand/or intracellular metabolism of vitamin A. Vitamin A is afat-soluble vitamin necessary for growth, reproduction,differentiation of epithelial tissues, and vision. RBP2 may alsomodulate the supply of retinoic acid to the nuclei of endometrialcells during the menstrual cycle.

MT-ND1 is the core subunit of the mitochondrial membrane respiratory chain NADH dehydrogenase (Complex I) that is believed to belong to the minimal assembly required for catalysis. Complex I functions in the transfer of electrons from NADH to the respiratory chain. The immediate electron acceptor for the enzyme is believed to be ubiquinone.$nDefects in MT-ND1 are a cause of Leber hereditary optic neuropathy (LHON) [MIM:535000]; also known as Leber optic atrophy. LHON is a maternally inherited d

p18 INK4c is a specific inhibitor of cdk4 / cdk6 (it interacts strongly with CDK6 and weakly with CDK4), and is expressed during G1 to S transition in the eukaryotic cell division cycle. It is maximally induced as cells enter S phase. Highest expression levels are found in skeletal muscle, but it is also found in the pancreas and heart.

MAG (myelin associated glycoprotein) is a Adhesion molecule in postnatal neural development that mediates sialic-acid dependent cell-cell interactions between neuronal and myelinating cells. Preferentially binds to alpha2,3-linked sialic acid. Isoform L-MAG is critical for the formation of myelin in the CNS, whereas isoform S-MAG is sufficient to maintain the integrity of myelin in PNS. Binds to RTN4R. single-pass type I membrane protein. Expressed by myelinating glial cells in the central ａn