JAG2 and chronic myelogenous leukemia, BCR-ABL1 positive: The results of our study show that co-culture between primitive CML cells and normal endothelial cells, without any additional factor, generates a microenvironment that allows for the in vitro maintenance of primitive CML cells through their permanence in a quiescent state, their proliferation and differentiation, which seem to be associated with the generation of an inflammatory environment, and their own adhesion abilities that could involve the Notch1–Jagged2 axis.