RARB and Fibroadenoma: RARβ gene expression was found to be significantly down-regulated in breast cancer (n = 101, 0.83 (0.04) Log10 RQ) compared to both normal (n = 27, 1.35 (0.09) Log10 RQ, p < 0.001) and fibroadenoma tissue (n = 32, 1.49 (0.07) Log10 RQ, p < 0.001, Additional file 1: Figure S1).