MIR142 and breast cancer: To eliminate the potential impact of the recipient mouse’s “endogenous” miR-142 wt T cells and to evaluate if even only a partial deficit of miR-142 as that observed in human T cells from BC CML patients could lead to reduced T cell-mediated antileukemic activity, we repeated the experiment by transplanting immunodeficient NSG recipients (CD45.1) that lack their own T cells, with Mir142−/−BCR-ABL LSKs (CD45.2, 104 cells/mouse) and Mir142−/−, Mir142+/− or Mir142+/+ T cells (CD45.2, 106 cells/mouse) selected from non-leukemic donors with the respective genotypes (Fig. 4c).