Three ion channel genes KCNK1, CLCN3, and CACNB3, which were overexpressed in breast cancer, and another ion channel gene ANO6, which was underexpressed in breast cancer, were identified by significance analysis of microarrays (SAM; Figs 1A, S1A, and S1B). The gene discussed is CACNB3; the disease is breast carcinoma.