Dr. Ahmad Reza Hosseinpoor is a medical doctor and an epidemiologist working at the World Health Organization in Geneva where he leads the work on health inequality monitoring. He has conceptualized and coordinated the development of resources and tools in this area including Health Inequality Monitor, the WHO global platform for disaggregated health data, WHO Health Equity Assessment Toolkit (HEAT), a software application to explore and compare health inequalities, and the WHO Handbook on Health Inequality Monitoring, a comprehensive resource to strengthen and guide the development of health inequality monitoring. He is the lead author of a number of peer-reviewed articles quantifying inequalities in health, both at the country level and the global level, as well as methodological articles on health inequality decomposition.