MFN1 and breast carcinoma: For example, there are higher levels of DRP1 and less Mfn1 (a GTPase for mitochondrial fusion) in the metastatic breast cancer cells compared with non-metastatic breast cancer cells.18 Silencing DRP1 or overexpression of Mfn1 results in mitochondrial fusion, and significantly suppresses migration and invasion abilities of breast cancer cells [18].