22748
Embryonic fibroblasts derived from the ser994 mutant mice were not sensitive to killing by a range of DNA damaging agents , but they were sensitive to the induction of sister chromatid exchanges induced by ultraviolet light or mitomycin C .
 Chemical: ser994; Chemical: mitomycin C
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: ser994; Chemical: mitomycin C