We tested the ex vivo cytotoxic activity of CD19-CAR T cells against RUNX1mut BP-CML blasts (i.e., CD34-positive cells) with and without imatinib using flow cytometry (Fig. 6a,, b and Supplementary Fig. 9a). This evidence concerns the gene CD19 and chronic myelogenous leukemia, BCR-ABL1 positive.