Two infants diagnosed with a relapsed form of childhood cancer who had previously exhausted all other treatment options remain disease-free after receiving a first-in-human experimental therapy that uses genetically engineered T cells, a new analysis reports. Such cell-based approaches have been difficult to implement in young children, a population in which B cell acute lymphoblastic leukemia (ALL) is highly prevalent, representing 25% of all pediatric cancer cases in the United States. Several options exist for treating ALL in children between the ages of one and 10, but infants less than one year old generally have much poorer prognoses. While modified or chimeric antigen receptor (CAR) T cells have proven to be highly effective in tackling ALL, these cancer-killing cells must be generated from each individual patient, which isn't feasible for those who do not have sufficient quantities of healthy T cells to start, like very young children. In search of a better alternative, Waseem Qasim and colleagues developed a novel approach that overcomes this significant obstacle to current T cell therapies. Instead of fine-tuning the infants' own T cells to fight their cancer, the researchers made a "universal" T cell that eradicated the leukemia from both subjects' blood. One study participant developed Graft-Versus-Host disease in the skin two months after the procedure, but the condition resolved after steroids and a bone marrow transplant; the second did not experience any significant complications associated with the regimen nor the bone marrow transplant received as a follow-up to the therapy. Both babies went into complete remission within 28 days after receiving the therapy, and have since remained leukemia-free for 10 and 16 months.