2303
Tumor cells showed an overexpression of p53 protein and were estrogen receptor -positive .
 ( protein: estrogen receptor, None) , ( protein: p53 protein, None) , ( cell type: Tumor cells, 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:
 ( protein: estrogen receptor, None) , ( protein: p53 protein, None) , ( cell type: Tumor cells, None) 