To evaluate the impact of silencing Rab27a and TRAF3IP2 in malignant breast cancer cells and their communication with MSCs, nude mice were injected with naïve MSCs into the 4th right mammary gland and either MDAw, MDAKDRab27a or MDAKDTRAF3IP2 cells in the contralateral mammary gland. The gene discussed is TRAF3IP2; the disease is breast cancer.