25892
Previous quantitative proteomic studies on the actions of 2 , 3 , 7 , 8 - tetrachlorodibenzo - p - dioxin ( TCDD ) in 5L rat hepatoma cells , a cell model frequently used for investigating the mechanisms of TCDD toxicity , had indicated that dioxin exposure reduced the abundance of numerous proteins which are regulated at the level of protein synthesis initiation .
 Chemical: 2 , 3 , 7 , 8 - tetrachlorodibenzo - p - dioxin; Chemical: TCDD; Chemical: TCDD; Chemical: dioxin
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: 2 , 3 , 7 , 8 - tetrachlorodibenzo - p - dioxin; Chemical: TCDD; Chemical: TCDD; Chemical: dioxin