Fig. 3From: Serum-derived factors of breast cancer patients with brain metastases alter permeability of a human blood–brain barrier modelBox plots of fractalkine serum concentrations in patients with different estrogen and progesterone receptor status of the tumour. The values of fractalkine concentrations (pg/ml) are shown on a logarithmic scale. ER estrogen receptor, PR progesterone receptor, *p < 0.05Back to article page