1837
PATIENTS : 33 HIV - infected , zidovudine - experienced patients with serum HIV RNA levels of at least 20 , 000 copies / mL and CD4 counts ranging from 50 to 400 cells / mm3 .
 GENE: CD4
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: CD4