PAK4 and gastric cancer: Furthermore, when CORO1C∆CE was overexpressed in gastric cancer cells, the localization of PAK4S99D in the plasma membrane was significantly reduced compared with gastric cancer cells overexpressing wild-type CORO1C (Figure 4A,D).This result suggested that although recruitment of PAK4 to the plasma membrane depends on both Ser99 phosphorylation and CE domain of CORO1C, there must be other mechanisms which prevent non-phosphorylated PAK4 from being recruited by CORO1C.