Another study demonstrated that premalignant lesion cells released a panel of proinflammatory mediators including CCL5, G-CSF, monocyte chemoattractant protein 1 (MCP-1), and prostaglandin-E2 (PGE2) in comparison to HNSCC/OSCC cells, indicating that the premalignant microenvironment is more immune stimulatory than the microenvironment of an established HNSCC/OSCC (416). This evidence concerns the gene CCL2 and head and neck squamous cell carcinoma.