TNF and infection: After 14 days post pulp exposure (infection), there were no differences in tumor necrosis factor alpha (TNF⍺) gene expression in the periapical lesion between Nav1.8-Cre and Nav1.8-DTA mice with both showing approximately a five-fold increase compared to healthy tissues (p = 0.35) (Fig. 2c) (n = 3 per group).