4586
Relative to untreated cultures , virus in cultures treated with oleandrin had significantly reduced expression of the envelope protein gp120 , the sole determinant of virus infectivity , suggesting a novel mechanism underlying the impaired infectivity .
 Chemical: oleandrin
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: oleandrin