1649
By extensive nucleotide sequence and Northern blot analysis , these cDNA clones were found to originate from approximately 42 different genes ( HZF 1-42 ) of which only 8 have previously been described.
 cDNA clones, HZF 1-42
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:
 cDNA clones, HZF 1-42