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The CD4 coreceptor interacts with non-polymorphic regions of major histocompatibility complex class II molecules on antigen-presenting cells and contributes to T cell activation .
 protein: CD4 coreceptor; protein: non-polymorphic regions; cell type: antigen-presenting cells; protein: major histocompatibility complex class II molecules
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: CD4 coreceptor, non-polymorphic regions, antigen-presenting cells, major histocompatibility complex class II molecules 
Answer:
 protein: CD4 coreceptor; protein: non-polymorphic regions; cell type: antigen-presenting cells; protein: major histocompatibility complex class II molecules