P2RX5 (purinergic receptor P2X 5), also known as P2X5/LRH-1 encodes a receptor for adenosine 5’-triphosphate (ATP) and adenosine that functions as a ligand-gated ion channel; this receptor can be aberrantly expressed in a subset of primary solid tumor specimens derived from renal cell carcinoma, brain cancer, colon and breast cancer patients (122, 123). Here, P2RX5 is linked to breast cancer.