Each year, an estimated 15,000 cancer patients in the United States alone die from infections and other complications while undergoing chemotherapy. To solve this lethal but all too common problem, Prateek Agarwal M20 WG20, Divyansh Agarwal GR23 M23, and Daniel Zhang GR23 M23 created Sanguis—the world’s first handheld, inexpensive blood-cell counting device. Winner of the 2018 Penn Wharton Startup Challenge, Sanguis uses just a few drops of blood to measure neutrophils, the body’s primary infection-fighting cells. The result? Patients can monitor their health and detect life-threatening conditions from home, potentially saving thousands of lives every year.