868
Tyrosine phosphorylation of cellular proteins is the earliest identifiable event following T - cell antigen receptor ( TCR ) stimulation and is essential for activating downstream signaling machinery .
 GENE: T - cell antigen receptor; GENE: TCR
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: T - cell antigen receptor; GENE: TCR