3507
OKT3 - induced human PBMC proliferation was determined by measuring ( 3 ) H - thymidine incorporation .
 ( 3 ) H - thymidine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ( 3 ) H - thymidine