PAK1 and gastric cancer: We demonstrate that PAK1-mediated MORC2 phosphorylation promotes cell cycle progression, defective phosphorylation of MORC2-S677A results in attenuated cell proliferation and tumorigenicity of gastric cancer cells, which is significantly enhanced in overexpression of phospho-mimic MORC2-S677E form, suggesting the importance of MORC2 phosphorylation in tumorigenesis.