13279
We have investigated, by the use of the reverse transcription polymerase chain reaction amplification technique , the possible existence of ER variants in other normal oestrogen target organs and cells, such as uterus ( myometrium and endometrium ), in peripheral blood mononuclear cells and in a benign uterus tumour ( leiomyoma ).
 ER, peripheral blood mononuclear cells
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 ER, peripheral blood mononuclear cells