We provide first in situ-ex vivo evidence of this concept in human CKD, with: [i] increased PTEC IL-1RI expression and senescence (SA-β-gal activity) in fibrotic kidneys; and [ii] positive correlations between numbers of senescent (SA-β-gal+) urinary PTECs and both urinary IL-1β levels and severity of interstitial fibrosis. The gene discussed is IL1B; the disease is chronic kidney disease.