Specifically, participants who walked more had trajectories reflective of less glomerular injury (lower urine albumin), better tubular function (lower urine A1M and TFF3), better tubular repair (higher urine EGF and UMOD), less tubular injury (urine IL-18 and NGAL), less generalized inflammation (TNFR1 and TNFR2), and less tubulointerstitial fibrosis/repair (urine MCP1 and clusterin). The gene discussed is IL18; the disease is fibrosis.