8703
Extinction of immunoglobulin gene expression in B cells upon fusion with HeLa cells is preceded by rapid nuclear depletion of essential transcription factors and is accompanied by widespread inactivation of genes expressed in a B cell-specific manner .
 ( cell type: B cells, None) , ( protein: essential transcription factors, None) , ( DNA: immunoglobulin gene, None) , ( cell line: HeLa 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:
 ( cell type: B cells, None) , ( protein: essential transcription factors, None) , ( DNA: immunoglobulin gene, None) , ( cell line: HeLa cells, None) 