Cellular retinoic acid binding protein (CRABP) in retinoblastoma.

Binding proteins for retinoic acid (cellular retinoic acid binding protein, CRABP) have been demonstrated in various cell types, and display the characteristics of receptors. Three retinoblastomas are described. The clinical diagnosis of retinoblastoma was established by ophthalmoscopic echographic and histological examination. One part of the tumor was frozen in liquid nitrogen immediately after surgery and used for the determination of CRABP. CRABP was present in cells from all three tumors. This may indicate sensitivity of this tumor to retinoic acid or synthetic retinoic acid derivatives with biologic activity.