TNF and infection: Additionally, the higher levels of mRNA expression found for the DEG of the NF- kB signalling pathway in Nc-Spain1H infection may be related to the observed variations in the expression of pro-inflammatory cytokines such as TNF, IL1B, IL6 and IL12B. Nc-Spain1H also induced enhanced expression of pro-inflammatory IL8 and of IL12A that was not observed for Nc-Spain7.