AP-2α isoform expression is differentially regulated in tamoxifen resistant cell lines and breast tumour samples. (a, b): Levels of AP-2α isoform 1a and 1c were determined by Western blot in a series of wild-type ER+ breast tumour lines and in their tamoxifen-resistant counterparts. The signal from a number of different non-saturated exposures was quantified with ImageJ and is graphically represented in (b). (c, d): Normal breast (4) and tumour samples (10) were analysed by real-time PCR for AP-2α isoform expression levels. The relative levels of AP-2α 1c normalised using GAPDH levels (c) and the ratio between AP-2α 1c and 1a (d) are represented. The differences remain statistically significant even when the outliers are eliminated from the analysis.