Invasive lobular and ductal carcinomas have been reported to lose or down-regulate ligand laminin 5 (LN5), a heterotrimeric laminin protein exclusive to epithelial cells that comprise three polypeptide chains produced by three distinct encoding genes such as the laminin alpha 3 gene LAMA3, the laminin beta 3 gene LAMB3, and LAMC2 [29]. This evidence concerns the gene LAMA3 and breast ductal adenocarcinoma.