Background: Breast cancer is the most common malignancy in women and the underlying mechanism of breast cancer cell metastasis is still far from uncover. Integrin subunit alpha 7  (ITGA7 ) is a functioning protein. It has been detected in many malignancies. But the function of ITGA7  in breast cancer is not clear. Our aim is to explore ITGA7  expression and its role in breast cancer. 
Methods: Real-time PCR was performed to determine ITGA7  expression in BC tissues and normal adjacent tissues. The specific functions of ITGA7  in breast cancer cell lines (MDA-MB-231 and BT-549) transfected with small interfering RNA were determined through migration, invasion assays. Western blot assays were performed to determine the expression of c-met and vimentin. 
Results: ITGA7  was down-regulated in breast cancer tissues compared to the adjacent normal tissues (T:N =7.68±27.38: 41.01± 31.47, P <0.001) and this observation was consistent with the TCGA cohort (T:N =4.51±0.45:5.40±0.61, P <0.0001). In vitro experiments showed that knocking down ITGA7  significantly inhibited the migration and invasion of the breast cancer cell lines (MDA-MB-231 and BT-549). Meanwhile, knockdown of ITGA7  promoted c-met and vimentin expression, which may induce invasion and migration.
Conclusion: ITGA7  plays an important tumorigenic function and acts as a suppress gene in breast cancer. Our findings indicate that ITGA7  was the gene associated with breast cancer.
Keywords: breast cancer, ITGA7 , migration, invasion