Recently, the single-arm phase II trial AALL1621 (ClinicalTrials.gov identifier: NCT02981628), conducted by the Children’s Oncology Group, showed that inotuzumab is effective and well tolerated in heavily pretreated children and adolescents (age of 1–21 years) with R/R CD22-positive BCP-ALL. The gene discussed is CD22; the disease is acute lymphoblastic leukemia.