Given our findings that suppression of α3β1 both reduces cell invasion and enhances RELN expression in breast cancer cells, together with reports that Reelin impairs cell invasion in other cancer cell types [23,32], we next wanted to determine whether loss of α3β1-dependent RELN repression, and the resulting increase in secreted Reelin, is sufficient to reduce invasive potential. Here, RELN is linked to breast cancer.