CD19 and acute myeloid leukemia: Consistent with the lack of CD19 expression in MV4;11:MSLN cells (data not shown), the mean AML cell load in the bone marrow of mice treated with non-specific BsAb CD19Blin-CD3L2K (55.0 ± 9.4%) was not significantly different from that of T cells alone (66.4 ± 6.7%).