These results demonstrated that virosecurinine effectively suppressed the proliferation of the human CML cell line K562 and suggested that growth inhibition may be in part due to virosecurinine-induced apoptosis through the downregulation of mTOR, BCR/ABL and SHIP2 and the upregulation of PTEN. Here, PTEN is linked to chronic myelogenous leukemia, BCR-ABL1 positive.