20115
Tumor necrosis factor - related apoptosis inducing ligand ( TRAIL ) is a pro - apoptotic ligand that has shown the exquisite ability to trigger extrinsic apoptosis in various types of cancer cells without significant toxicity toward normal cells , when compared to other pro - apoptotic ligands such as tumor necrosis factor ( TNF ) alpha or Fas ligand .
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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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