The activation of TLR4 [33] in collecting ducts [34], mediated by NF-κB-mediated signaling [35], via bacterial LPS, has been shown in our earlier work to induce LCN2 upregulation and SLC22A17 downregulation in mIMCD3 cells, and suggested to protect IMCD cells against bacterial infections, and prevent autocrine death induction by LCN2 [20]. Here, LCN2 is linked to bacterial infectious disease.