Previous work demonstrated that Drp1-dependent mitochondrial fission regulates metastasis of breast cancer cells.17 We found that IFN-γ treatment resulted in mitochondrial elongation and induction of GBP2 expression, with little change in Drp1 expression or Mfn1 and Mfn2 in the indicated cells (Supplementary Figure 2b). Here, MFN1 is linked to breast cancer.