TNF and cancer: Many mediators of inflammation are known to impact on nociceptors enhancing their excitability: histamine, bradykinin, leukotrienes, and prostaglandins from mast cells; adenosine, ATP, and protons from damaged tissues; IL-1β, IL-6, TNF-α, and NGF from macrophages (62); endothelin-1 and NGF from cancer cells.