17969
These results support the rationale of pharmacologically inhibiting COMT to aid with smoking cessation among Val / Val genotype smokers . The Pharmacogenomics Journal advance online publication , 5 March 2013 ; doi : 10 . 1038 / tpj . 2013 . 1 .
 Chemical: Val; Chemical: Val
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: Val; Chemical: Val