Patients
Seventy-four newly diagnosed pediatric BCP-ALL patients (aged<18 years) with IKZF1 gene deletions, who underwent initial treatment in our institution between June 2014 and January 2018 were included in this study. All patients met the morphology-immunology-cytogenetics-molecular (MICM) criteria [4]. The level of IKZF1 Δ2-8/ALB deletions in bone marrow (BM) samples were detected by multiplex real-time quantitative PCR (RQ-PCR), as described in a previous study[5]. A patient with a IKZF1 deletion was defined as having IKZF1 Δ2-8/ALB deletions of ≥ 0.01% of the BM sample at diagnosis. Clinical characteristics, laboratory data, and treatment outcomes were analyzed. The study was approved by the Ethics Committee of Peking University People’s Hospital, and the guardians of all patients provided written informed consent.