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The site - specific DNA inversion system Cin encoded by the bacteriophage P1 consists of a recombinase , two inverted crossing - over sites and a recombinational enhancer .
 Cin, recombinase
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 Cin, recombinase