6983
All tissues and cells studied were homozygous for the wild-type gene , and were heterozygous as well as homozygous for the codon-10-variant type .
 wild-type gene, codon-10-variant type
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:
 wild-type gene, codon-10-variant type