<qa>  What is the downstream effector of TGF-b?Implicated in the development of CAN in rodents and humans is transforming growth factor beta TGF-beta, a pleiotropic cytokine which is elevated in CAN recipients, and stimulates matrix deposition within the graft. A downstream effector of TGF-b is connective tissue growth factor CTGF, which has been recently associated with other fibrotic renal diseases. In preliminary studies in a mouse model of CAN, CTGF gene expression is increased in kidney transplants with CAN. However, its role in human CAN is unknown. 