7965
Tissues from women undergoing elective termination of uterine pregnancy and from women with ectopic pregnancy were used to detect the presence of cells important for the maintenance of pregnancy, such as BCL-2+ , CD56+ , CD3+ , CD8+ and CD68+ cells , and the presence of oestrogen ( ER ) and progesterone receptors ( PR ) by immunohistochemistry .
 oestrogen, oestrogen ( ER ) and progesterone receptors, progesterone receptors, PR, ER
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:
 oestrogen, oestrogen ( ER ) and progesterone receptors, progesterone receptors, PR, ER