TGFB1 and chronic kidney disease: Abbreviations: BUN = blood urea nitrogen, CBM = Chinese Biomedical Literature Database, CKD = chronic kidney disease, CNKI = China National Knowledge Infrastructure, Embase = Excerpt Medical Database, ESRD = end-stage renal disease, RCTs = randomized controlled trials, RIF = renal interstitial fibrosis, Scr = serum creatinine concentration, TGF-β1 = transforming growth factor-β1, ECM = extra cellular matrix, VIP = China Science and Technology Journal Database.