12495
Age - adjusted linear regression models showed statistically significant positive associations between exposure to one or more of the PFC totals and / or individual analytes and the following immunological parameters : absolute numbers of CD2 + T cells , CD4 + helper T cells , CD19 + immature B cells , CD21 + mature B cells , CD2 / CD21 ratio , MHCII + cells , B cell proliferation , serum IgG1 , granulocytic , and monocytic phagocytosis .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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