13692
Furthermore, while ligand-activated c-erbA/TR accelerated differentiation , unliganded c-erbA/TR effectively blocked differentiation and supported sustained progenitor growth in culture.
 c-erbA/TR, c-erbA/TR
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:
 c-erbA/TR, c-erbA/TR