Thus, TNF-α-deficient (TNF-α−/−) or TNF-R2-deficient (TNF-R2−/−) mice exhibited greatly reduced chronic anemia compared with WT or TNF-R1-deficient (TNF-R1−/−) mice (41, 59), suggesting that TNF-R2 signaling mediates infection-associated pathology, whereas TNF-R1 signaling has little or no impact on the T. brucei infection. This evidence concerns the gene TNF and infection.