In the case of tuberculosis (TB), which kills upwards of 1.4 million people a year, researchers are using DNA sequencing and CT scans in mummies to understand what conditions TB thrives in and how to treat it. Work from Haagen Klaus, a biological anthropologist at George Mason University, suggests that, contrary to what some experts think, Europeans might have brought a particularly deadly form of TB to the Americas. His preliminary DNA data hints that Peruvian remains dating back to the 10th century—before Spanish explorers arrived—might have been infected with a more benign strain of the TB bacteria Mycobacterium tuberculosis, or a different species altogether, Mycobacterium kansasii. And many studies have shown that the bodies of Central Americans from before and after European contact rarely, if ever, show signs of TB symptoms. Klaus subscribes to the hypothesis that this may be because M. tuberculosis thrives in the presence of iron, and these people ate a low-iron diet with little meat. If true, this insight could point to new drugs that would inhibit M. tuberculosis from taking up iron.