Recent research shows that Syndecan-1 has roles variably in the regulation of TME (Handra-Luca, 2020), and the shed of SDC1 not only acts as an autocrine factor in the TME to stimulate tumor cell migration and angiogenesis, but also as a novel paracrine immunosuppressive mechanism to promote the extravasation and survival of malignant tumors (Jung et al., 2019). Here, SDC1 is linked to cancer.