MRD detection
MRD detection was performed by real-time quantitative PCR, and some common fusion transcripts, such as ETV6/RUNX1, E2A/PBX1, and BCR-ABL1, were assessed using reverse transcription PCR. Karyotyping screening was performed using a conventional karyotyping (G-banding) analysis or fluorescence in situ hybridization (FISH). Monitoring of BM samples for MRD, common fusion transcripts and IKZF1 Δ2-8/ALB deletions monitoring of BM sample was carried out every 2–3 months during the first 3 years after diagnosis. After which these criteria were assessed every 6 months for 2 years.