Drp1 expression is high in metastatic breast cancer, and clinical findings have demonstrated that ER-negative carcinomas usually proliferate faster12 and are more inclined to nodal metastasis than are ER-positive neoplasms.39 Thus high Drp1 expression in breast tumors may be promoting high rates of proliferation and metastasis. The gene discussed is DNM1L; the disease is carcinoma.