6773
We report that two 20-epi analogues , MC1627 and MC1288 , induced differentiation and transcription of p21 ( Waf1 , Cip1 ), a key VDR target gene involved in growth inhibition, at a concentration 100-fold lower than that of 1,25(OH)2D3 .
 p21, VDR target gene, VDR, Cip1, Waf1
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:
 p21, VDR target gene, VDR, Cip1, Waf1