TGFB1 and chronic kidney disease: This prospective cohort study aims to quantify GAS5 expression across CKD fibrosis stages, compare its diagnostic accuracy with established markers (e.g. eGFR, TGF-β1) and imaging-based fibrosis scores, and elucidate the mechanistic basis of its dual-tissue regulation (plasma/urine dynamics), thereby bridging molecular insights with clinical validation to establish GAS5 as a novel, accessible biomarker for fibrosis and redefine management paradigms in CKD.