IL3 and chronic myelogenous leukemia, BCR-ABL1 positive: Indeed, expression of Bcr-Abl in cytokine-dependent cell lines leads to growth factor-independent proliferation associated with autocrine production of interleukin-3 (IL-3) and granulocyte/monocyte-colony stimulating factor [38–40], and increased levels of IL-3 are detected in serum in murine models of CML [36,37].