3171
Previously , we have shown that the human ( h ) beta ( 1 ) AR is cleaved in its N terminus by a metalloproteinase , both constitutively and in a receptor activation - dependent manner .
 Chemical: N
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: N