11596
Viral DNA synthesis and late gene expression were found to be defective in U937 cells infected with E1B 19K mutants compared with wild-type virus .
 ( protein: E1B 19K, None) , ( cell line: U937 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: E1B 19K, None) , ( cell line: U937 cells, None) 