14714
Although several class II promoter-specific DNA binding factors have been described, only the X box region factor, RFX , shows a genetic correlation with class II expression , being deficient in some B cell lines derived from patients with class II-deficient congenital immunodeficiency .
 ( protein: RFX, None) , ( DNA: X box region, None) , ( protein: class II promoter-specific DNA binding factors, None) , ( cell line: B cell lines, 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: RFX, None) , ( DNA: X box region, None) , ( protein: class II promoter-specific DNA binding factors, None) , ( cell line: B cell lines, None) 