Uromodulin has various biological functions, including protection against urinary stone formation [11,12] and urinary tract infection [13,14,15,16], and regulation of sodium reabsorption through the activation of the Na+–K+–2Cl− cotransporter (NKCC2) and sodium chloride cotransporter (NCC) [17,18,19]. The gene discussed is UMOD; the disease is urolithiasis.