6204
Sequence comparison indicates that exons 5 ' / L and L / N in PSG12 and PSG12 psi are 99 % identical , except that the L / N exon in the PSG12 psi gene contains a stop codon .
 PSG12, PSG12 psi, PSG12 psi gene
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 PSG12, PSG12 psi, PSG12 psi gene