TNF and cancer: In the medical condition subgroups, a significant decrease in TNF-α levels was observed in the cancer (SMD = −0.66; 95% CI, −2.42 to 1.11) and MD (SMD = −0.66; 95% CI, −1.61 to 0.30) groups, but only a slight decrease was observed in the CNS group (SMD = −0.10; 95% CI, −0.34 to 0.13) (Table 3).