14270
There were two main goals: (1) to evaluate whether workers with a moderately increased PCDD/PCDF -body burden [25-140 ppt TCDD or 104-522 ppt I-TE in blood fat ] exhibit changes in the surface receptors of white blood cells , as observed in previous studies in non-human primates , and (2) to clarify whether persons at the upper range [10-23 ppt TCDD or 30-90 ppt I-TE in blood fat ] of the body burden reference values of a not particularly exposed population show detectable deviations in these immunological variables , when compared with persons at the lower and medium range [1-3 ppt TCDD or 9-29 ppt I-TE ] of these body burden reference values .
 ( protein: surface receptors, None) , ( cell type: white blood 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: surface receptors, None) , ( cell type: white blood cells, None) 