For the 4.5 million people who need a blood transfusion each year, this is big news. Researchers report that they’re making substantial progress on figuring out how to transform any blood type into type O—the blood type that can be transfused to any patient. The key lies in a special enzyme created by scientists that removes substances on red blood cells that cause the body to reject blood of a different type, thus reducing the likelihood of a fatal immune reaction. Though the enzyme isn’t ready to begin large-scale conversions of blood types A or types B, the researchers say there’s hope of improving the enzyme’s ability to do so within the next five to ten years. In spite of the wait, the enzyme sounds promising, especially given that only 37 percent of the U.S. population is eligible to donate blood though less than 10 percent donate annually, according to Would the success of this enzyme potentially impact you or anyone you know? Share your thoughts with us in the comments.