GA not only overcome the multidrug resistance of PTX by inhibiting P-gp activity in MCF-7/ADR cells, but also inhibited MDA-MB-231 cells migration and invasion in vitro, playing a crucial role in preventing and treating the lung metastasis of breast cancer caused by PTX; meanwhile, the synergistic anti-tumor effect of GA and PTX has also been verified in vitro and in vivo experiments. The gene discussed is PGP; the disease is breast cancer.