1973
The phorbol ester , PMA , was also a potent inducer of Fos kinase activity in all of the above populations, suggesting that PKC plays a role in the regulation of this enzyme .
 protein: Fos kinase; protein: enzyme; protein: PKC
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: Fos kinase, enzyme, PKC 
Answer:
 protein: Fos kinase; protein: enzyme; protein: PKC