Increased syndecan-1 in lung microenvironments accelerated the outgrowth of mammary carcinoma metastases, whereas higher syndecan-1 levels inhibited lung carcinogenesis by regulating exosome miRNAs, and lung cancer patients with higher syndecan-1 levels were more likely have better prognoses [27, 28]. This evidence concerns the gene SDC1 and breast carcinoma.