Preservation of mitochondrial integrity is essential for prevention of cell death (1, 2). Brain metastases are a clinical problem in patients with breast cancer (3-5). We mined published microarray data (6, 7) to discover genes associated with brain metastasis in patients with brain metastatic breast cancer. We found that the gene encoding optic atrophy 1, OPA1, a gene with functions in the stabilization of the mitochondrial cristae (8), was among the genes most differentially expressed in the brain metastases of patients with brain metastatic breast cancer. OPA1 may be of relevance to the biology underlying metastasis to the brain, and it may be of relevance as a potential therapeutic target in patients with intractable disease.