MTDH and breast cancer: Next, Brown and Ruoslahti (10) used a phage expression library of complementary deoxyribonucleic acid (cDNA) from a mouse model of the lung metastasis of breast carcinoma to identify a lung homing peptide in AEG-1/MTDH that was overexpressed in metastatic breast cancer and promoted the homing of breast cancer cells to the lungs.