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.

Input: Consider Input:  Interestingly , VDR was able to bind to VDREs with high affinity and to fully activate transcription in intact yeast cells in the presence of the retinoid X receptor ( RXR ) .

Output: retinoid X receptor


Input: Consider Input:  Vibrio cholerae iron transport : haem transport genes are linked to one of two sets of tonB , exbB , exbD genes .

Output: exbD genes


Input: Consider Input:  To examine the biochemical mechanism of Tax1 transactivation , we have developed an in vitro transactivation assay in which wild - type Tax1 is able to specifically transactivate a polymerase II promoter through upstream Tax1 - responsive elements .


Output: polymerase II