Subsequently, this conjecture was confirmed based on the following: (1) SOCS6 was confirmed to be a target gene of miR-21-5p; (2) upregulation of SOCS6 inhibited malignant cellular phenotypes of BC cells; (3) silencing of SOCS6 separately reversed the regulatory roles of miR-21-5p knockdown on malignant cellular phenotypes in BC cells. This evidence concerns the gene SOCS6 and breast cancer.