TNF and neoplasm: A recent study has shown that administration of levo-tetrahydropalmatine (l-THP) [27] at the dose of 60 mg/kg significantly prevented and/or reversed bone cancer-related pain behaviors, and inhibited tumor cell implantation-induced activation of microglial cells and the increased levels of tumor necrosis factor (TNF)-α and interleukine (IL)-18 [18].