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Here, we tested whether the potency of one class of compounds, 20-epi analogues , to induce myeloid cell differentiation, is because of direct molecular effects on vitamin D receptor ( VDR ).
 VDR, vitamin D receptor
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 VDR, vitamin D receptor