2077
Based upon this observation , 2 - year drinking water studies were conducted to assess the carcinogenic potential of an Aloe vera whole - leaf extract when administered to F344 / N rats ( 48 per sex per group ) at 0 . 5 , 1 , and 1 . 5 % , and B6C3F1 mice ( 48 per sex per group ) at 1 , 2 , and 3 % .
 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