TVA1 cells expressed typical B-ALL markers (CD10+CD19+CD20+; Supplementary Figure 4), proliferated without growth factors or stromal support, and retained in vitro sensitivity to dasatinib in cytotoxicity assays (Figure 4A–4B) and high basal pSTAT5 by phosphoflow cytometry analysis (data not shown). Here, CD19 is linked to acute lymphoblastic leukemia.