4872
We identified 158 outlier genes as early predictive and surrogate markers for predicting each tested PAH by combination of two different multi - classification algorithms with 100 % accuracy through a leave - one out cross - validation method .
 Chemical: PAH
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: PAH