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Therefore, we analyzed the expression, DNA binding, and transcriptional activity of the endogenous RA and VitD3 receptors [ retinoic acid receptors ( RARs ), retinoid X receptors ( RXRs ), and VitD3 receptor ( VDR )] in the U-937 cell line , in which RA and VitD3 induce distinct monocytic differentiation pathways .
 retinoic acid, VDR, VitD3 receptor, retinoic acid receptors, retinoid X receptors, endogenous RA and VitD3 receptors, U-937 cell line, RARs, RXRs
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:
 retinoic acid, VDR, VitD3 receptor, retinoic acid receptors, retinoid X receptors, endogenous RA and VitD3 receptors, U-937 cell line, RARs, RXRs