1229
Two putative Rev proteins with apparent molecular masses of 18 and 16 kDa were expressed by p2 / 2 and p176 , while p20 expressed only a 16 - kDa species .
 GENE: Rev proteins; GENE: p2 / 2; GENE: p176; GENE: p20
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: Rev proteins; GENE: p2 / 2; GENE: p176; GENE: p20