Inhibitor of cell differentiation 1 (ID1), matrix metallo-proteinase 1 (MMP1), chemokine CXC motif ligand 1 (CXCL1), prostaglandin-endoperoxide synthase (PTGS2), vascular cell adhesion molecule-1 (VCAM1), and epiregulin (EREG) were among the genes that promote lung metastasis in animal models carrying breast carcinoma, and their differential expression was able to differentiate among breast cancer patients, those with lung metastases vs those without. This evidence concerns the gene PTGS2 and breast carcinoma.