TGFB1 and chronic kidney disease: UPC in cats is an independent predictor of CKD progression (Chakrabarti et al., 2012) and survival (Syme et al., 2006), and if increased urine protein is a contributing factor to, rather than a marker of, progressive renal damage, some of the negative effects could be mediated by the upregulation of inflammatory or pro-fibrotic mediators, such as TGF-β1.