RARB and breast cancer: Contrary to what was found in the above study of Lin and co-workers on breast cancer [179], the transfection with exogenous retinoid receptors RXRα and RARα restored the H1792 growth-inhibition by ATRA and 9-cis RA through the antagonism of AP-1 activity, whereas RARγ was less effective, and RARβ was ineffective [155].