GPX1 and chronic myelogenous leukemia, BCR-ABL1 positive: Based on the observation that GPx-1 activity could be enhanced by tyrosine phosphorylation and inhibited using the Bcr-Abl small molecule inhibitor imatinib [10], we explored the possibility that patients being treated for chronic myelogenous leukemia (CML), a form of leukemia characterized by the Bcr-Abl translocation and treated with imatinib, would possess mononuclear blood cells with decreased GPx activity.