Fig. 2. Myofibroblast marker expression is dependent on Lkb1. (A) SMA immunofluorescence staining of MEFs treated for 72 hours with TGFβRI inhibitor (SB431542), indicating a requirement for TGFβ signaling in SMA expression by primary MEFs. (B,C) Staining of SMA (B) and SM22 (C) in control and Lkb1^–/– MEFs, demonstrating decreased myofibroblast marker expression in the absence of Lkb1. Nuclear Hoechst stains are shown to demonstrate comparable cell numbers. (D) Phalloidin and vinculin staining, demonstrating a decrease in the amount of stress fibers and the mislocalization of focal adhesions in Lkb1^–/– MEFs. (E) Quantitation of the percentage of wrinkling cells in each genotype, showing the average out of three experiments. Error bars indicate s.d.; ^*P<0.05.