2448
Matrix metalloproteinases can collectively cleave all components of the extracellular matrix , with the endogenous tissue inhibitor of metalloproteinase - 1 regulating their activity .
 extracellular matrix
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Anatomy 
Text: {0} 
Answer:
 extracellular matrix