Fig. 4. Effect of CD9 on TGF cell-surface expression in 3D cell cultures. MDCK cells expressing CD9, TGF or both proteins were embedded in Engelbreth-Holm-Swarm (EHS) tumor basement membrane extract and grown until cysts had formed. The cells were fixed and stained for CD9 or TGF, and immunofluorescence images were captured using confocal microscopy. Scale bars: 20 µm.