TNF and infection: However, an enhanced upregulation of 9 genes, all involved in the NF-kB pathway (CCL2/MCP1, CCL20, CCL4, CXCL2/MIP2α, IL1A, NFKBIA, PTX3, TNFA, TNFAIP3), was observed after infection with D26 variants, in comparison to the WT (Figure 4(B)).