On the other hand, blockade of macropinocytosis by knocking down PAK1 reduced siRNA AMC6-mediated siRNA uptake by 35%, indicating that macropinocytosis is the major mechanism for AMC6-siRNA nanocomplex uptake into glioblastoma cells and that the combined action of the other two major endocytic pathways cannot fully compensate for macropinocytosis blockade. This evidence concerns the gene PAK1 and glioblastoma.