4243
The arginyl peptide bonds that are cleaved in the conversion of human factor IX to factor IXa by factor XIa were identified as Arg145 - Ala146 and Arg180 - Val181 .
 human factor IX, factor IXa, factor XIa
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 human factor IX, factor IXa, factor XIa