14398
Alternative splicing ( AS ) is one of the most significant components of the functional complexity of human UDP - glucuronosyltransferase enzymes ( UGTs ) , particularly for the UGT1A gene , which represents one of the best examples of a drug - metabolizing gene regulated by AS .
 UDP
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 UDP