In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.
Q: Consistent with this observation , introduction of Smad sites into a TGFbeta - insensitive LEF1 / TCF target gene confers cooperative TGFbeta and Wnt responsiveness to the promoter .
A:
Smad sites