Fig. 2

Examples of tamoxifen localization in experimental model analysis showing the precursor ion (m/z 372.233) distribution in an ER-negative (left panels) and an ER-positive (right panels) phenotype tissue section. The dotted lines define the areas covered by tumor cells as determined by a pathologist in H and E images (a). The extracted ion maps of the tamoxifen precursor ion were normalized on TIC and the same intensity scale was used to compare tumor sections. The tumor and stroma ROIs, that were used for quantitative comparison, were highlighted in yellow (b) and red (c), respectively