IL6 and infection: Following the construction of a new U937 KO (S2 Table) and confirmation that this DNA-PK KO had impaired recognition of the known agonist CpG but not the unrelated poly I:C, E. coli LPS, PAM, and flagellin (S6D Fig), we observed that DNA-PK was important for TNFα, but not IL-6, production by L. pneumophila-infected macrophage at 9 h after infection (Fig 8B).