However in the presence of 6 or 7 cytokines (KL + FL + TPO, each 50 ng/ml, + G-CSF + GM-CSF + IL-3 ± IL-6, each 10 ng (ml), viability remains excellent (95–100%) and the majority of both normal and CML total CD34+ cells and G0 and G1/S/G2/M cells are induced to proliferate rapidly in liquid culture with average doubling times of ~30 hours. This evidence concerns the gene TPO and chronic myelogenous leukemia, BCR-ABL1 positive.