7806
Cleavage of transcription factor SP1 by caspases during anti-IgM-induced B-cell apoptosis .
 SP1, caspases, transcription factor, B-cell
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:
 SP1, caspases, transcription factor, B-cell