75%. siRNA transfection into MCF7 or MDA-MB231 cells (at 5 × 105 cells per well of a 6-well plate) was conducted using 7.5 µL TransIT-X2 Transfection Reagent (Mirus, Madison, WI, USA) with 25 nM of siRNAs per well. 4.7. Cell Viability Assay Both 3-(4,5-dimethylathiazol-2...