The data obtained by the GeneChip Exon array (Affymetrix) demonstrated that the KCNMA1 gene was over-expressed in breast cancer cell lines derived from human breast cancer metastases to brain (MDA-MB-361) as compared to metastatic breast cancer cells derived from systemic organs (MDA-MB-231) or primary breast cancer (MCF-7) (Figure 1). Here, KCNMA1 is linked to breast cancer.