University of California, San Diego researchers have discovered that the skin of mice can sense low levels of oxygen and regulate the production of erythropoietin (EPO), the hormone that stimulates our bodies to produce red blood cells and allows us to adapt to high-altitude, low-oxygen environments.

They found breathing in one concentration of oxygen and exposing skin to another concentration triggered the body to produce its own EPO. If the results apply to humans, the discovery could radically change the way physicians treat anemia and other diseases that require boosting our bodies’ ability to produce red blood cells.