Given the task definition and input, reply with output. 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.

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 ) .
retinoid X receptor