8502
Lysates from CD19 cross-linked 1E8 cells induced robust phosphorylation of an Elk-1 fusion protein in vitro, whereas no phosphorylation of Elk-1 fusion protein occurred using lysates from CD19 cross-linked BLIN-1 cells .
 1E8 cells, Elk-1, CD19 cross-linked BLIN-1 cells, Elk-1, Elk-1 fusion protein, Elk-1 fusion protein, CD19, CD19
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:
 1E8 cells, Elk-1, CD19 cross-linked BLIN-1 cells, Elk-1, Elk-1 fusion protein, Elk-1 fusion protein, CD19, CD19