The Leukemia Lymphoma Society (LLS) Pediatric Acute Leukemia (PedAL) Initiative is a collaborative international effort that aims to improve the cure of children with relapsed/refractory (R/R) and other high-risk leukemias. Its comprehensive approach included preclinical and clinical research, standardization and improvement of diagnostics, quality management, and global data integration and analysis. The European Pediatric Acute Leukemia (EuPAL) Foundation was established as the PedAL Initiative partner to support European stakeholders in these efforts.