NFKB1 and infection: Recently, several articles showed that the virulence of L. pneumophila strains with invasion and proliferation ability is positively correlated with the level of NF-κB activation in the host after infection, and those strains that can induce a higher NF-κB activation level in vitro lead to more weight losses, higher mortality, more serious pathological phenotypes, and higher levels of serum cytokine production in A/J mice [31,32].