20668
This difference is due to the ability of Tyr 319 to suppress ZAP - 70 activity even when the SH2 domains are dislodged from the kinase domain , providing stringent control of ZAP - 70 activity downstream of Lck .
 Chemical: Tyr
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: Tyr