3218
mRNA levels of receptor activator of nuclear factor kappa - B ( RANK ) , its ligand RANKL , tumor necrosis factor alpha ( TNF - alpha ) and RANKL / osteoprotegerin ( OPG ) ratio were diminished in the periodontium of CCL3 ( - / - ) mice and in the group treated with Met - RANTES .
 Met
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Met