18711
Exposure to E2 caused a significant increase in VTG concentrations which corresponded with the gene expression of VTG and estrogen receptor ( ER ) in males , which were further elevated after combined exposure to E2 and KTC , indicative of a synergetic relationship .
 Chemical: E2; Chemical: estrogen; Chemical: E2; Chemical: KTC
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: E2, estrogen, E2, KTC 
Answer:
 Chemical: E2; Chemical: estrogen; Chemical: E2; Chemical: KTC