Because CD151 is primarily expressed in the mammary myoepithelial cells and the PyMT tumors arise from luminal epithelial cells in the mammary gland where CD151 has reduced expression, it is tempting to speculate that Cd151 deletion could affect tumor development indirectly through the microenvironment, by modifying the phenotype of the myoepithelial cells. This evidence concerns the gene CD151 and neoplasm.