One group transiently expressed an mRNA CAR construct targeting CD33 to avoid prolonged toxicity [65], whereas another clinical study is currently ongoing in which T cells expressing anti-CD123 CARs via mRNA electroporation were infused into patients with AML (ClinicalTrials.gov number, NCT02623582) to evaluate efficacy and safety. The gene discussed is CD33; the disease is acute myeloid leukemia.