Our results demonstrate that PAK4 confers CDDP resistance in gastric cancer cells via the activation of MEK/ERK (MAPK or mitogen-activated protein kinase/extracellular-signal-regulated kinase) and PI3K/Akt (phosphoinositide 3-kinase/protein kinase B or PKB) pathways. The gene discussed is MAP2K7; the disease is gastric cancer.