LTBP4 and ductal breast carcinoma in situ: The extracellular matrix protein latent TGF-β binding protein 4 (LTBP4) is downregulated in human and murine ductal carcinomas in situ, invasive mammary carcinomas [17], [24], as well as in canine mammary carcinomas [25], indicating a possible phylogenetic conserved regulation of LTBP4 expression.