In conclusion, our data from the in vivo mammary carcinoma model support the previous evidence for the tumour suppressor role of ColXV and advocate that the effect of ColXV in tumourigenesis is not due to the anti-angiogenic properties of its restin domain but rather because of its protective effect on tumour ECM remodelling and subsequent consequences in tumour cell behaviour. This evidence concerns the gene COL15A1 and breast carcinoma.