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All of the parameters were also tested for correlation, and a significant inverse correlation was found between age and type I and type II receptors when all subjects were plotted and between aged and CD4 and age and CD4/CD8 in the aged group .
 cell type: CD4; cell type: CD4/CD8; protein: type II receptors; protein: type I
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 cell type: CD4; cell type: CD4/CD8; protein: type II receptors; protein: type I