The kidney tubules make up the vast majority of the kidney’s cortical structure, expend most of the energy used by the kidneys, and play a central role in a variety of essential biological functions. However, chronic kidney disease (CKD) diagnosis, staging, and prognosis remain anchored to estimated glomerular filtration rate (eGFR) and albuminuria, which primarily reflect glomerular health and do not fully capture tubular pathology.1 Biopsy-proven interstitial fibrosis and tubular atrophy is found in nearly all forms of CKD, and its severity is strongly prognostic of kidney failure.