Cellular retinol-binding protein in normal and neoplastic human mammary gland.

The concentration of cellular retinol-binding protein (CRBP) was determined in samples of normal and neoplastic mammary gland, using a specific and sensitive radioimmunoassay. The CRBP concentration was significantly higher in neoplastic tissue, but detectable levels were also present in all samples of normal gland. Tubulo-ductal cancers had significantly lower CRBP levels than other cancer types. The CRBP concentration of the neoplastic tissue showed no correlation with the concentration of progesterone or estrogen receptor.