30577
In order to decrease the probability of false peptide identification , only peptides with significance scores above the identity threshold ( at the 95 % confidence interval ) , defined by Mascot probability analysis ( www . matrixscience . com / help / scoring _ help . html # PBM ) , were considered to be confidently identified and used for protein identification . Furthermore , only proteins identified in all four iTRAQ samples through at least two peptides with a p - value of < 0 . 05 ( expectation value ) were further analyzed " .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None