We evaluated the prognostic and therapeutic significance of measurable residual disease (MRD) during remission induction in pediatric acute lymphoblastic leukemia (ALL) patients. In the CCCG-ALL-2015 protocol, 7640 patients were categorized into low-, intermediate-, or high-risk groups based on clinical and genetic features. Final risk classification was determined by MRD assessed via flow cytometry on Days 19 and 46 of remission induction, with additional intensified chemotherapy for Day 19 …