Get off the No. 7 train at the Seventy fourth Street-Broadway stop, in Queens, walk past La Abundancia Bakery, the Bollywood Beauty Salon, the New Hae Woon Dae Korean restaurant, the offices of Vishwanath Puttaswamygowda, M.D., and then past the New York Seventh-Day Adventist Chinese church (advertising free conversational-English classes), and you will find yourself at Elmhurst Hospital Center, in Elmhurst, the most diverse neighborhood in New York City and maybe in the world. The hospital serves 1.7 million patients a year, and offers translation services in a hundred and fifty-three languages. The Colombians, Bangladeshis, Koreans, Belarussians, Burmese, Chinese, Vietnamese, Croatians, Mexicans, and other immigrants who live nearby use Elmhurst for their care, and their communities back home often know about the hospital as well. It is not unusual for the exotically sick to fly to LaGuardia or J.F.K. from overseas to check in to Elmhurst. Diseases rare enough to merit special-case-study attention in The New England Journal of Medicine are, at Elmhurst, relatively common. If a young Southeast Asian is brought to the emergency room one morning because he is suddenly unable to move, even a junior physician knows to list familial periodic paralysis—an obscure disease that is considerably more common in the Philippines—as a possible diagnosis. An ambitious pedagogue of medicine couldn’t dream up a more diverse patient population for physicians-in-training.