Having identified a mechanism linking the trafficking regulators RAB5, RAB7A, and GDI2 to αVβ6-mediated and HER2-mediated invasion, which is dysregulated following acquired trastuzumab resistance, we next analyzed breast cancer patient data to determine the impact of expression of RAB5, RAB7A, and GDI2 in HER2+ breast cancer. This evidence concerns the gene GDI2 and breast cancer.