CXCR4 and neoplasm: Representative photos of the H&E-stained cores from different tumour subgroups, together with composite images of the CXCR4-CCR7 dimers (PLA signals) on EpCAM-expressing mammary epithelial cells are shown in Figure 4A. Quantified numbers of PLA signals per area of breast epithelium was then correlated with the grade, stage, and lymph node status to the corresponding tumours (Figure 4B).