PECAM1 and neoplasm: When the xenograft volumes reached approximately 100:mm3, we intravenously injected CCL22 (0.1 μg/kg; twice/week) and treated the animals with VS-6063 for approximately three consecutive weeks and observed tumor growth, AKT activity, and the expression of various markers of malignant tumor progression, including Ki67 (a marker of proliferation), LYVE-1 (a marker of lymphatic vessels), and CD31 (an endothelial marker).