By employing polyclonal antibodies against various epitopes in the NTD domain -that are available now at a research level [21, 41]-, it should be possible to further validate our assays of COL11A1 RNA variants and to evaluate findings on the differential proteolysis of the N-terminal regions of the protein chain of collagen a1(XI) in breast cancer and their involvement in tissue remodeling through stereochemistry. This evidence concerns the gene COL11A1 and breast carcinoma.