Cellular retinoic acid-binding protein 1 is a protein that in humans is encoded by the CRABP1 gene. CRABP1 is assumed to play an important role in retinoic acid-mediated differentiation and proliferation processes. It is structurally similar to the cellular retinol-binding proteins, but binds only retinoic acid. CRABP1 is constitutively expressed and is believed to have different functions in the cell than the related CRABP2.