15048
Activation of MAPKs by other receptor tyrosine kinases also resulted in phosphorylation of Ser ( 777 ) in FGFR1 , thereby enabling crosstalk regulation of FGFR activity by other signaling pathways .
 Chemical: tyrosine; Chemical: Ser
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: tyrosine; Chemical: Ser