[Uromodulin]: Functions in biogenesis and organization of the apical membrane of epithelial cells of the thick ascending limb of Henle's loop (TALH), where it promotes formation of complex filamentous gel-like structure that may play a role in the water barrier permeability (Probable). May serve as a receptor for binding and endocytosis of cytokines (IL-1, IL-2) and TNF (PubMed:3498215). Facilitates neutrophil migration across renal epithelia (PubMed:20798515). {ECO:0000269|PubMed:20798515, ECO:0000269|PubMed:3498215, ECO:0000305}. [Uromodulin, secreted form]: In the urine, may contribute to colloid osmotic pressure, retards passage of positively charged electrolytes, and inhibits formation of liquid containing supersaturated salts and subsequent formation of salt crystals (By similarity). Protects against urinary tract infections by binding to type 1 fimbriated E.coli (PubMed:11134021, PubMed:32616672). Binds to bacterial adhesin fimH which mediates the stable formation of bacterial aggregates, prevents the binding of E.coli to uroplakins UPK1A and UPK1B which act as urothelial receptors for type I fimbriae, and allows for pathogen clearance through micturation (PubMed:11134021, PubMed:32616672). Also promotes aggregation of other bacteria including K.pneumoniae, P.aeruginosa and S.mitis and so may also protect against other uropathogens (PubMed:32616672). {ECO:0000250|UniProtKB:Q91X17, ECO:0000269|PubMed:11134021, ECO:0000269|PubMed:32616672}. This is the function of UMOD (uromodulin, ENSG00000169344).