CD33 and acute myeloid leukemia: CD33-CAR-NK cells were more potent in eliminating OCI-AML2 and CD33-positive primary AML cells in a short-term killing assay compared to UTD-NK cells (Fig. 1E, F; Supplementary Fig. 1A), while killing of the CD33-dim KG1a cell line was not improved (Supplementary Fig. 1B).