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By introducing a cDNA library derived from rat embryonic fibroblast cells , we isolated several morphologically flat revertants of rat 3Y1 cells transformed by the E6 and E7 genes of human papillomavirus type 18 ( HPV18 ) .
 Anatomy: embryonic fibroblast cells; Anatomy: revertants; Anatomy: 3Y1 cells
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Anatomy 
Text: {0} 
Answer:
 Anatomy: embryonic fibroblast cells; Anatomy: revertants; Anatomy: 3Y1 cells