Acute lymphoblastic leukemia (ALL) accounts for 25% of all pediatric cancer cases in the United States. There are several options for treating ALL in children aged 1-10 years, but infants under one year of age generally have a much poorer prognosis. However, two infants diagnosed with ALL are cured after receiving initial experimental therapy using CAR T cells. This treatment has been difficult to implement in young children because although CAR T cells have been shown to be very effective in fighting ALL, these cancer-targeting cells must be generated from the patient’s own cells, which is not feasible for those who do not have sufficient amounts of healthy T cells, such as very young children. In order to find a better alternative, researchers have developed a new approach based on CAR T cells. Instead of modifying infants’ own T-cells to fight their cancer, the researchers made a “universal” T-cell. However, one of the infants developed graft-versus-host disease two months after receiving treatment, but the condition resolved after steroid injections and a bone marrow transplant. The second did not experience any significant complications associated with the treatment or the bone marrow transplant received as a follow-up to the treatment.