Specificity of hormonal responsiveness in vitro. Effect of sex steroids on non-malignant rat cells compared with the effect on cells from rat tumours.

Since mammary tumours and sarcomas in the rat both have been shown to be sensitive to steroid hormone in vitro, a search for a non-steroid sensitive rat tissue was made. Neonatal cerebellar medulloblasts in the rat did not respond to high concentrations of steroids if cultured as organ culture. The relevance of this finding to the specificity of steroid response assays in vitro is discussed.