We first assessed the expression of the fusion markers mitofusins 1 and 2 (Mfn1 and Mfn2) and optic atrophy type 1 (Opa1), as well as expression of the fission marker dynamin-related protein 1 (Drp1) in cell lines MCF7 representative luminal A subtype of BC, MDA-MB-231 representative basal-like subtype of BC, and MCF10A as a non-tumorigenic (control) (Figure 1A) [7]. The gene discussed is MFN1; the disease is breast cancer.