Fig. (2) Expression of Influenza M2 in cell lines HT1080 and LCL114. Cells were transduced with retroviral construct expressing a deletion variant of M2 (Δ29-31, Δ62), that is less cytotoxic (A and B), or an empty retroviral construct (C and D). M2 was stained with the 14C2 monoclonal antibody and an anti-mouse HRP.