Researchers from the University of California, San Francisco made a startling discovery about lungs, and published their findings in Nature: The organ plays an important role in blood production. In studies, scientists saw the lungs of mice making a whole lot of blood platelets—about 10 million per hour. Platelets are the cells that circulate within our blood and bind together to clot and stop bleeding when he have a cut.

That 10-million-per-hour number means the lungs make the majority of the platelets in the circulation in mice. This shatters our decades-long belief that bone marrow makes all of our blood components. "What we've observed here in mice strongly suggests the lung may play a key role in blood formation in humans as well," says one of the researchers, Mark R. Looney.

You would think we would've figured this out by now, right? Well, this discovery was made possible by a new type of technology based on "two-photon intravital imaging." (That same tech was also recently used to discover an unidentified function of the cerebellum.) Plus, there are still plenty of scientific anomalies that occur in our bodies — specifically in the brain. Next up, scientists will begin looking at how the lungs and bone marrow work together as a blood factory. All of this new information could be hugely beneficial for the way we treat blood diseases.