IL3RA and acute myeloid leukemia: All cell lines expressed CD123, except parental EL4 cells and OCI-Ly19 (Fig 4A). To evaluate the functionality of CD123-specific CAR+ T cells in vitro, we used a 4-hour chromium release assay for AML cell lines (Fig 4B) and a flow cytometry-based killing assay for primary AML cells (Fig 4C and 4D).