XCL1 and pyelonephritis: Three studies found median chemokine (C-X-C Motif) ligand 1 (CXCL-1) to be between 10 and 38 times higher in samples from a mixed population of patients with UTI, cystitis, febrile UTI compared with controls.44,49,60 Median levels of sTNFR-1 were between 2 and 10 times higher in samples from patients with pyelonephritis or febrile UTI than in those from healthy controls, whilst median sTNRF-2 was between 3 and 7 times higher.37,43,58