6460
Two-color immunohistochemistry demonstrated that both macrophages and fibroblast-like synoviocytes were positive for nuclear C/EBP beta .
 ( cell type: fibroblast-like synoviocytes, None) , ( cell type: macrophages, None) , ( protein: C/EBP beta, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( cell type: fibroblast-like synoviocytes, None) , ( cell type: macrophages, None) , ( protein: C/EBP beta, None) 