image: This is a schematic view of the different cell types that make up the milk ducts of the human breast. Estrogen and progesterone are hormones that are made by the ovaries, circulate in the blood and reach the breast in low amounts. Only about 30 percent of the cells in the milk ducts have antennae (ER, PR) that allow them to detect estrogen and progesterone. These cells make the proteinRANKL when they "see" progesterone. RANKL is release and reaches the neighboring cells and tells them to proliferate. This image relates to a paper that appeared in the April 24, 2013, issue of Science Translational Medicine, published by AAAS. The paper, by Dr. T. Tanos at Ecole Polytechnique Fédérale de Lausanne in Lausanne, Switzerland, and colleagues was titled, "Progesterone/RANKL Is a Major Regulatory Axis in the Human Breast." view more
Credit: Image courtesy of Cathrin Brisken