12974
The high concentration of foreign antigen in the lumen of the gastrointestinal tract is separated from the underlying lymphocytes by a single cell layer of polarized epithelium .
 cell type: lumen; protein: foreign antigen; cell type: lymphocytes
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: lumen, foreign antigen, lymphocytes 
Answer:
 cell type: lumen; protein: foreign antigen; cell type: lymphocytes