According to the following experimental results, we found that overexpression or knockdown of KCNK1 did not affect the resting potentials of MDA-MB-231 and MCF-7 cells, and the resting potential of these cells did not change significantly after quinine treatment (S3H and S3I Fig), which indicated that the effect of KCNK1 on the malignant phenotype of breast cancer cells is independent of its voltage effect. This evidence concerns the gene KCNK1 and breast cancer.