13550
Our data showed that LH effectively inhibited mitotic proliferation of Hey1B cells ( half maximal inhibitory concentration = 1 . 2 mu M ) with very low toxicity , resulting in cell cycle arrest at the G2 / M transition through enhanced expression of the cell cycle inhibitor p21 and marked down - regulation of cyclin D3 expression .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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