1974
Upstream of the afa - 3 gene cluster , a 1 . 2 - kb region was found to be 96 % identical to the RepFIB sequence of one of the enterotoxigenic E . coli plasmids ( P307 ) , suggesting a common ancestor plasmid .
 GENE: afa - 3 gene cluster; GENE: RepFIB sequence
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: afa - 3 gene cluster; GENE: RepFIB sequence