Performing Western blot analyses of CXCL13 and CXCR5 expressions on lysates of six randomly selected breast cancer samples and four healthy breast tissue samples, we observed a weak but constantly detectable expression of the chemokine receptor CXCR5 in tumour samples, whereas protein expression of this chemokine receptor was not detectable in the healthy samples analysed (Figure 2C). Here, CXCL13 is linked to breast carcinoma.