Tannic acid, a gallotannin found in several natural sources, plays a role in various cancer signaling pathways, including the JAK/STAT, RAS/RAF/mTOR, TGF-β1/TGF-β1R axis, VEGF/VEGFR, and CXCL12/CXCR4 axes (35). Here, CXCR4 is linked to cancer.