A number of specific carrier proteins for members of the vitamin A family have been discovered. Cellular retinoic acid binding proteins (CRABP) are low molecular weight proteins whose precise function remains unknown. The inducibility of the CRABP2 gene suggests that this isoform is important in retinoic acid-mediated regulation of human skin growth and differentiation. It has been postulated that the CRABP2 gene is transcriptionally regulated by a newly synthesized regulatory protein.