900
All the three compounds showed moderate cytotoxicity against four cancer cells , KB ( a human epidermal carcinoma ) , MCF7 ( human breast carcinoma ) , SK - LU - 1 ( human lung carcinoma ) and HepG2 ( hepatocellular carcinoma ) .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None