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The human platelet-activating factor receptor ( PAFR ) gene is transcribed by two distinct promoters ( promoter 1 and promoter 2 ) to generate two transcripts (designated as PAFR transcript 1 and PAFR transcript 2 ), though their open reading frames are identical.
 PAFR, human platelet-activating factor receptor, human platelet-activating factor receptor ( PAFR ) gene, PAFR, PAFR transcript 2, promoter 2, promoter 1, PAFR, promoters, PAFR transcript 1
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:
 PAFR, human platelet-activating factor receptor, human platelet-activating factor receptor ( PAFR ) gene, PAFR, PAFR transcript 2, promoter 2, promoter 1, PAFR, promoters, PAFR transcript 1