Therefore, the Bertozzi group has developed a new conceptual antibody-enzyme drug, bi-sialidase fusion protein (E-602), which is trastuzumab (anti-HER2 mAb)-conjugated with neuraminidase that cleaves sialic acids on HER2+ cancer cells, resulting in an enhanced ADCC activity and immune cell activation upon desialylation in the TME in local tumor site in preclinical studies (Figure 4) [284,285]. Here, ERBB2 is linked to cancer.