9845
The pre-leukemic phase of Friend erythroleukemia results from activation of the erythropoietin receptor ( EpoR ) by the spleen focus forming virus (SFFV) envelope glycoprotein , followed by the emergence of leukemic clones characterized by overexpression of Spi-1 and mutation of the p53 tumor suppressor gene .
 ( protein: Spi-1, None) , ( DNA: p53 tumor suppressor gene, None) , ( protein: EpoR, None) , ( protein: erythropoietin receptor, None) , ( protein: spleen focus forming virus (SFFV) envelope glycoprotein, 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: Spi-1, None) , ( DNA: p53 tumor suppressor gene, None) , ( protein: EpoR, None) , ( protein: erythropoietin receptor, None) , ( protein: spleen focus forming virus (SFFV) envelope glycoprotein, None) 