Cells are also able to modify their internal structure, and need to express specific proteins to that end. As we demonstrated above, the condensation of F-actin produced internal compartments in the GUVs. Intrigued by this phenomenon, actin was expressed in the presence of fluorescently-labelled phalloidin (Figure ), to promote the polymerization of actin even at low concentrations 86 and allow its visualization. At the same conditions of the pre-encapsulated actin, we could observe actin condensation leading to internal compartments, but with seemingly looser structures than with the former (Figure , Figure ), suggesting once again that the interplay between actin and the membrane induced changes in the GUV structure.