5726
Loss of both cytolytic susceptibility and sensitization to chemically induced apoptosis was coselected during in vivo selection of E1A -positive sarcoma cells for increased tumorigenicity .
 E1A -positive sarcoma cells, E1A
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 E1A -positive sarcoma cells, E1A