KDR and neoplasm: Highly sulfated polysaccharides show stronger anti-angiogenic and anti-tumor effects, as their negative sulfate groups interact with positively charged cell-surface proteins (e.g., EGFR, MMPs, VEGF/VEGFR), blocking tumor metastasis, angiogenesis, and invasion (Mazepa et al., 2022; Zheng et al., 2022).