Further study confirmed that TGFβ/Smad signal involved in the upregulation of GDF15 on the expressions of maspin and NDRG1 in bladder carcinoma cells, since being pretreated with the inhibitor of TGFβ/Smad pathway, SB431542 or LY364947, which not only blocked the activation of TGFβ on the phosphorylation of Smad 2/3 and Smad 1/5 but also attenuated both the inhibitory effect of TGFβ and activation of GDF15 on the expressions of maspin and NDRG1 in bladder carcinoma cells (Figure 1, Figure 2 and Figure 5). Here, TGFB1 is linked to urinary bladder carcinoma.