8259
However , one CAK - phosphorylated phosphopeptide comigrates with a Cdc2 - phosphorylated phosphopeptide previously shown to be mitosis - specific , suggesting that , in vitro , CAK is able to phosphorylate at least one site that is also phosphorylated in vivo .
 CAK, Cdc2, CAK
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 CAK, Cdc2, CAK