POSTN and cancer: By interacting with the growth factor VEGF-A and binding to EC integrins (αvβ3, αvβ5, and α6β4) and cancer cells, POSTN activates intracellular signaling pathways (PI3K, AKT/PKB, FAK, and Erk/VEGF), which leads to increased cell survival, angiogenesis, invasion, and metastasis.