Two radioresistant BC (RBC) cell lines (MCF7/C6 and MDA-MB-231/C4) isolated from surviving MCF7 and MDA-MB-231 residues with HER2 induction and aggressive phenotype after chronical radiation (Figure S1A) (8, 35) showed enhanced expressions of mitochondrial FAO genes CPT1A, CPT2, HADHB, and ACAD9 (Figure 1A). Here, ACAD9 is linked to breast cancer.