1532
All six ARF cDNAs are more similar to each other than to other approximately 20 - kDa guanine nucleotide - binding proteins .
 ARF cDNAs, 20 - kDa guanine nucleotide - binding proteins
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 ARF cDNAs, 20 - kDa guanine nucleotide - binding proteins