Fig. 2From: Hydroxyurea Optimization through Precision Study (HOPS): study protocol for a randomized, multicenter trial in children with sickle cell anemiaHOPS study sites. HOPS is a multi-center trial that is performed at 11 pediatric sickle cell centers across the USA. Cincinnati Children’s Hospital Medical Center serves as the study sponsor and Medical and Data Coordinating CenterBack to article page