Fig. 3From: Intratumoral heterogeneity as a source of discordance in breast cancer biomarker classificationRepresentative images of ER staining in four cores and the tissue section from which they were removed, in a case with manually confirmed heterogeneous ER expression. Note the variability in staining across the whole tissue section, which is reflected in the variable expression levels in the four cores. ER estrogen receptorBack to article page