Importantly, our finding that these cells fail to respond properly to chemical (e.g. EGF) and physical (e.g. adhesion signals) stimuli in the absence of BCAR3 could have significant implications for treatment of breast cancers that express this protein, as it may be possible to target BCAR3 (or other molecules within the BCAR3/Cas/c-Src signaling network) in the tumors with limited collateral damage to other tissues. Here, BCAR3 is linked to breast carcinoma.