Subsequently, on the basis of this observation, an interesting study implicating the use of a mouse mammary cancer model found that tumor cells overexpressing Mena, a cytoskeletal regulatory protein, in conjunction with a perivascular macrophage and an endothelial cell, constituted a microanatomic landmark of a portal leading to carcinoma cell intravasation (termed tumor microenvironment of metastasis—TMEM). This evidence concerns the gene EGFR and breast cancer.