7569
Differential inhibition of Smad6 and Smad7 on bone morphogenetic protein- and activin- mediated growth arrest and apoptosis in B cells .
 cell type: B cells; protein: Smad7; protein: Smad6
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: B cells, Smad7, Smad6 
Answer:
 cell type: B cells; protein: Smad7; protein: Smad6