CDKN1A and breast cancer: Especially in breast cancer, several reports have found that MTDH could increase lung metastasis of breast cancer cell[2], promote chemoresistance and metastasis by 8q22 genomic gain[18], associate with poor overall survival and promote the proliferation of breast cancer cells through downregulation of tumor suppressor and cell-cycle inhibitor genes, p21Cip1 and p27Kip1, possibly via Akt/FOXO1 signaling[13,20].