HER-2: human epidermal growth factor receptor-type 2; BthTX-I: bothropstoxin I;PLA2: phospholipase A2; RPMI-1640: Roswell ParkMemorial Institute 1640; FBS: fetal bovine serum; CML: chronic myeloid leucemia;CS-FBS: charcoal-stripped fetal bovine serum; MTT:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide; DMSO: dimethylsulfoxide; PI: propidium iodide; FACS: fluorescence-activated cell sorting; HFS:hypotonic fluorescent solution; SD: standard deviation; IC50: halfmaximal inhibitory concentration; CSC: cancer stem cells; Caspase:cystein-dependent aspartate-specific protease. This evidence concerns the gene ERBB2 and chronic myelogenous leukemia, BCR-ABL1 positive.