To obtain the bone marrow-like conditions, we opted for the co-culture model, which allows intercellular cross-talk and interactions between human erythroleukemia K562 or primary CD34 + CML cells growing in suspension and HS-5 stromal cells growing as an attached layer (Fig. 1A). This evidence concerns the gene CD34 and chronic myelogenous leukemia, BCR-ABL1 positive.