4682
Histologic regression of EH was observed in 27 ( 79 . 4 % ) and 33 ( 97 . 5 % ) cases at 12 and 36 months , respectively .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None