Fig. 7D shows that Bcl-2 overexpression significantly reduces compression-induced cell death in the spheroids while crmA over-expression has little effect. Similarly, overexpression of crmA in a highly metastatic murine breast carcinoma cell line EMT6, which has a high level of endogenous Bcl-2 expression [18], did not further protect from compression-induced caspase-3 activity (data not shown), suggesting that the mitochondrial pathway regulates solid stress-induced apoptosis. This evidence concerns the gene CRMA and breast carcinoma.