1768
Moreover , Hg ( 2 + ) led to an arrest of the cells in the S phase of the cell cycle .
 Chemical: Hg ( 2 + )
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: Hg ( 2 + )