TGFB1 and chronic kidney disease: As the evidence that pathways described herein (i.e., TGF-β1 and Wnt/β-catenin) are directly associated to fibrosis and the progression of CKD in humans and in mice previously infected by L. interrogans becomes clearer, it is questionable whether chronic and asymptomatic leptospiral infection is related to CKDu, as well as whether it contributes to the progression of CKD to end-stage kidney disease.