A Specialized CD4+ T-Cell Subset Protects Residual Leukemic Cells from Immune Surveillance, Enabling Relapse

Outcomes for patients with acute lymphoblastic leukemia (ALL) continue to improve in the era of immune- therapies. Despite this, measurable residual disease (MRD) frequently persists after frontline treatment, necessitating allogeneic hematopoietic stem cell transplantation or prolonged chemotherapy lasting multiple years. Relapse remains common and is associated with long-term survival rates of <25%. This emphasizes the need for research into fundamental mechanisms that enable the persistence of leukemic blasts.