Chronic diseases including heart disease, diabetes, and cancer, are the leading cause of death worldwide, with the burden falling heaviest in low- and middle-income countries. A new article by Harvard School of Public Health researchers outlines the global burden of chronic, or noncommunicable, diseases and proposes ways in which national leaders and heads of international organizations can develop systems to cope with these long-term conditions that the authors call the “dominant global public health challenge of the 21st century.”