In addition, our previous study in murine kidney infection has shown a large-scale association between C5aR1 and Man on the luminal surface of the renal tract epithelium by confocal microscopy (Li et al., 2017); this, together with the fact that C5aR1 is an N-linked glycosylated protein, raises the possibility that C5aR1 itself as a mannose-containing glycoprotein may function as a carbohydrate ligand for UPEC and mediate type 1 fimbriae-dependent bacterial adhesion/colonization. The gene discussed is C5AR1; the disease is pyelonephritis.