1631
In the United States high - MW HES 480 which is difficult to degrade is most frequently used and results in a larger in vivo MW and subsequent decrease in factor VIII / von Willebrand factor levels .
 GENE: factor VIII; GENE: von Willebrand factor
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: factor VIII; GENE: von Willebrand factor