We performed luciferase reporter tests to show that SRY‐Box 9 (Sox9) is the target of miR‐215‐5p; as predicted, Sox9 depletion replicates the suppressive effects of miR‐215‐5p on breast carcinoma cells, and overexpression of Sox9 rescues the effects of miR‐215‐5p on breast cancer cell progression. This evidence concerns the gene SOX9 and breast cancer.