CXCR4 and cancer: Emodin is an effective inhibitor of inflammatory markers, which play a pivotal role in cancer development, such as nuclear factor kappa B (NF-ĸB), tumor necrosis factor (TNF-α), interleukines (IL)-1β, IL-6, IL-8, chemokine receptor C-X-C motif chemokine receptor 4 (CXCR4), adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), and angiogenic factors, such like VEGF.