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Estrogen receptor positive ( ER+: MCF-7 ) and negative ( ER-: MDA-MB-231 ) human breast cancer cell lines were utilized to evaluate the effects of tamoxifen ( TAM ) and estradiol ( E2 ) on modulation of breast cancer target susceptibility to lysis by lymphokine-activated killer (LAK) cells .
 cell line: ER+: MCF-7; cell line: human breast cancer cell lines; cell line: ER-: MDA-MB-231; cell type: lymphokine-activated killer (LAK) cells; cell line: Estrogen receptor positive ( ER+: MCF-7 ) and negative ( ER-: MDA-MB-231 ) human breast cancer cell lines
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 cell line: ER+: MCF-7; cell line: human breast cancer cell lines; cell line: ER-: MDA-MB-231; cell type: lymphokine-activated killer (LAK) cells; cell line: Estrogen receptor positive ( ER+: MCF-7 ) and negative ( ER-: MDA-MB-231 ) human breast cancer cell lines