Q: 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.
Transient transfection assays indicated that the ( - 4551 ) UCP1 - CAT construct , containing the 5 ' - regulatory region of the rat ucp - 1 gene , was activated by PPARalpha co - transfection in a dose - dependent manner and this activation was potentiated by Wy 14 , 643 and retinoid X receptor alpha .
A:
retinoid X receptor