The first direct evidence of the involvement of the endogenously expressed CaSR in the secretion of multiple cytokines and growth factors by metastatic breast cancer cells was reported by Hernández-Bedolla et al. They reported that CaSR activation in MDA-MB-231 cells transactivated EGFR and stimulated the secretion of endothelial chemotactic and pro-angiogenic factors like GM-CSF (granulocyte-macrophage colony stimulating factor), EGF (epidermal growth factor), MDC (macrophage-derived chemokine), FGF-4 (fibroblast growth factor-4), and IGFBP-2 (insulin-like growth factor-binding protein-2). The gene discussed is FGF4; the disease is breast cancer.