In the light of MDR1 directly contributing to the drug resistance by exporting drugs out of the cell, combined with our results showing that galectin-1 enhances the chemoresistance in CML, we proposed that galectin-1 may decrease the chemosensitivity via increase of MDR1 expression. Here, ABCB1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.