Who drinks blood and avoids direct sunlight? Not just Edward Cullen. It’s also, maybe once upon a time, people with Erythropoietic protoporphyria (EPP). The authors of a new study on EPP’S genetic origin suggested, somewhat fancifully, that in ancient times people with the disorder may have coped by drinking blood and staying indoors until dark. Su erers blister (but don’t sparkle) in the sun and experience severe anemia.