PON2 and chronic myelogenous leukemia, BCR-ABL1 positive: In vitro investigations showed that the enzyme is overexpressed in the Lama84 and KCL22 CML cell lines resistant to imatinib compared with sensitive counterparts and that PON2 upregulation is mediated by Lef-1 through activation of the Wnt/GSK3β/β-catenin pathway [41].