Chemotherapy at the wheel of ALL relapse

In this issue of Blood, Li et al(1) present an extensive in-depth genetic characterization of diagnostic, relapse, and remission samples from a cohort of 103 pediatric patients with acute lymphoblastic leukemia (ALL) treated according to the Shanghai Children's Medical Center ALL-2005 frontline protocol. Together with data obtained from 208 serial bone marrow samples collected during ALL therapy, their work suggests that relapse in a fraction of childhood ALL patients is driven by chemotherapy-induced mutations, which impact therapy response.