MFN1 and breast carcinoma: Mitochondria are dynamic organelles, which continually change shape through the combined action of fission, fusion, and movement along cytoskeletal tracks.[qv: 22] Our results indicate that expression of MFN1/2 was elevated in shBRCA1 cells compared to shCtrl cells in the absence of CCCP treatment (Figure S2D, Supporting Information), suggesting that BRCA1 might regulate mitochondrial dynamics in breast cancer cells.