To investigate whether specific depletion of THRα or THRα1 affects breast cancer cell proliferation or viability, as was observed with dronedarone treatment, the six representative cell lines were transfected with siRNA targeting THRα (GE Dharmacon SMARTpool), THRα1 (pool of 4 siRNA, GE Dharmacon), or a non-targeting control. This evidence concerns the gene THRA and breast cancer.