20
The inability of E1A gene products to induce cytolytic susceptibility during infection was not explained by an inhibitory effect of viral infection on otherwise susceptible target cells or by viral gene effects on class I MHC antigen expression on target cells .
 ( cell type: target cells, None) , ( cell type: target cells, None) , ( DNA: viral gene, None) , ( DNA: E1A gene, None) , ( protein: class I MHC antigen, 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: target cells, None) , ( cell type: target cells, None) , ( DNA: viral gene, None) , ( DNA: E1A gene, None) , ( protein: class I MHC antigen, None) 