KDR and cancer: Catalpol also synergizes with chemotherapeutic and adjuvant agents to induce cancer control, including regorafenib in liver cancer and chloroquine in gastric cancer, promoting increased anticancer action via upregulated cancer cell apoptosis, decreased proliferation, and inhibited angiogenesis via PI3K/p-Akt/mTOR/NF-κB, VEGF/VEGFR2, and Bax signaling pathways modulation.