19750
Disruption of 5 - HT2A receptor - dependent signaling in mice was associated with decreased acetylation of histone H3 ( H3ac ) and H4 ( H4ac ) , and increased tri - methylation of histone H3 at lysine 27 ( H3K27me3 ) at the mGlu2 promoter - epigenetic changes that correlate with transcriptional repression .
 Chemical: lysine
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: lysine