Several groups have recently initiated clinical trials of CD19/CD22 bispecific CART cell products in children with B-ALL (https://clinicaltrials.gov/ identifiers NCT03330691, NCT03241940, NCT03448393, and NCT03289455), which hold the promise of reducing the frequency of relapse driven by antigen loss. The gene discussed is CD22; the disease is acute lymphoblastic leukemia.