8915
Regulation at 37 degrees C , therefore , involves the action of three protein kinase cascades that repress HSF1 through phosphorylation of serine residues 303 , 307 , and 363 and may promote growth by suppressing the heat shock response .
 HSF1
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 HSF1