TNF and neoplasm: Lidocaine administered systemically (30 mg/kg) to mice with melanoma decreased tumor growth by inducing apoptosis in endothelial cells.42 Furthermore, lidocaine in clinically relevant concentrations enhanced the function of NK cells and inhibited the production of IL-6, tumor necrosis factor (TNFα), and IL-12 from activated dendritic cells.43,44 In humans, the use of scalp blocks for GBM surgery was associated with a lower neutrophil to lymphocyte ratio, suggesting a modulatory effect of regional anesthesia on inflammation.45