SMAD3 and renal carcinoma: The lysates of human renal carcinoma (ACHN) cells were used to detect the degradation of recombinant Smad3 by PROTAC in vitro since ACHN cells contained very high pVHL protein level [3].Western blot results showed that the degradation of Smad3 was related to the amount of PROTAC (Fig. 1B).