6307
Oct-1 , a POU domain transcription factor , was identified as a repressor of HLA-DRA promoter activity in the Rb-defective cells .
 ( cell type: Rb-defective cells, None) , ( protein: POU domain transcription factor, None) , ( protein: Oct-1, None) , ( DNA: HLA-DRA, 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: Rb-defective cells, None) , ( protein: POU domain transcription factor, None) , ( protein: Oct-1, None) , ( DNA: HLA-DRA, None) 