STAT3 and infection: Interestingly, upregulated expression of IL-1β, IL-6, and TNF-α, and sustained activation of the STAT1, STAT3, and JNK pathways, both occur in LCN2-knockout mice along with an increase in the susceptibility to infection with Klebsiella pneumoniae or Escherichia coli in the liver and in mice with breast cancer [33, 34].