BCR and chronic myelogenous leukemia, BCR-ABL1 positive: But, despite elevated SOCS2 expression in patients, SOCS2 was found to be dispensable for BCR-ABL induced CML and for normal hematopoietic stem cell function in mice.[28] To examine the impact of cytokines in BCR-ABL mediated transformation and leukemogenesis, we used SOCS1 as an inhibitor.