ACTB and breast carcinoma: In order to identify potential motor proteins that directly associate with ZBP1 and contribute to the transport process of β-actin mRNA, we prepared extracts from MDA231 breast carcinoma cells in which a FLAG-GFP-tagged human ZBP1 gene was genetically inserted (Gu et al., 2012), treated the cell extracts with RNase I and used anti-FLAG IgG-coated Sepharose to pull down proteins associated with ZBP1.