3963
However , it is only loosely associated , or not associated , with viral particles . gp170 is generated by an alternatively spliced Env mRNA using a splice donor and splice acceptor pair localized within the env open reading frame ( ORF ) , which is normally used to generate Bell and Bet transcripts derived from the internal promoter within the env ORF . gp170 is expressed at a level 30 to 50 % of the Env precursor gp130 .
 GENE: gp170; GENE: Env mRNA; GENE: env open reading frame ( ORF ); GENE: Bell; GENE: Bet transcripts; GENE: env ORF; GENE: gp170; GENE: Env precursor; GENE: gp130
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: gp170; GENE: Env mRNA; GENE: env open reading frame ( ORF ); GENE: Bell; GENE: Bet transcripts; GENE: env ORF; GENE: gp170; GENE: Env precursor; GENE: gp130