OPN1SW and acute lymphoblastic leukemia: In a long‐term follow‐up analysis of two cohorts in r/r BCP‐ALL, 70% of all relapse‐free survivors received HSCT, and 30% of all relapse‐free survivors did not16; for further trials with blinatumomab in r/r BCP‐ALL, there is no long‐term follow‐up available to thoroughly address this issue.