4328
We found that helenalin markedly induced endoplasmic reticulum ( ER ) stress - related genes , such as regulated in development and DNA damage responses ( REDD ) 1 , activating transcription factor - 4 ( ATF4 ) and / or the CCAAT enhancer - binding protein - homologous protein ( CHOP ) .
 Chemical: helenalin
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: helenalin