It has recently been reported that PGC-1α is involved in regulating mitochondrial function and metastasis of breast cancer cells.6 As PGC-1α is a target for miR-485-3p and miR-485-5p, we first sought to investigate the functional roles of miR-485-3p and miR-485-5p in regulating mitochondrial respiration of breast cancer cells. This evidence concerns the gene PPARGC1A and breast cancer.