The Bill & Melinda Gates Foundation has awarded a Grand Challenges Explorations Grant to a WCM project that will help researchers study antimicrobial resistance in fifty-four cities worldwide. The grant, which provides $100,000 in its first phase, will enable scientists to develop maps of the cities’ genetic differences as well as their epigenetic states (which detail how genes are turned on or off). To do so, investigators will sequence DNA, RNA, and microbes collected from subways, buses, parks, beaches, sewer systems, and other locations in cities including New York, Boston, Stockholm, Shanghai, Hong Kong, and Moscow. The project was kicked off in June with an event called Global City Sampling Day, when more than 400 people on six continents collected thousands of samples. “This work is so exciting because there is this entire invisible world around us that we can now start to bring into focus,” says Christopher Mason, PhD, an associate professor of physiology and biophysics and of computational genomics in the HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine and the WorldQuant Foundation Research Scholar, who oversaw a similar study in New York City’s subway system in 2015. “The genetic and epigenetic maps that we’ll develop will be invaluable for public health, disease surveillance, and the planning of smarter cities in the future.”