In search for transcriptional mechanisms that may explain the previously observed IM-associated downregulation of Separase protein levels in CML [13] followed by posttranslational hyperactivation of Separase proteolytic activity, we have analyzed the conditional context between c-MYB expression, Separase and IM treatment. Here, ESPL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.