CP and breast cancer: Importantly, when engrafted into congenic normal wt CD45.1 recipients, LSKs from both miR-142−/−BCR-ABL and miR-142+/−BCR-ABL mice (CD45.2) recapitulated the BC phenotype whereas LSKs from miR-142+/+BCR-ABL donors recapitulated the CP phenotype (Fig. 2d, e), suggesting that miR-142 deficit had stably transformed CP-LSCs into BC-LSCs.