3180
These transcripts directed the synthesis of three proteins : the virus trans - activator protein ( EIAV Tat ) encoded by ORF S1 , a protein of unknown function encoded by ORF S2 , and the virus envelope glycoprotein .
 GENE: virus trans - activator protein; GENE: EIAV Tat; GENE: envelope glycoprotein
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: virus trans - activator protein; GENE: EIAV Tat; GENE: envelope glycoprotein