Studies have suggested that peonidin 3-glucoside (P3G), as a kind of flavonoids, can inhibit lung cancer cells in a variety of ways, such as lowering the extracellular signal-regulated kinase (ERK) pathway to inhibit H2199 cell invasion, inhibiting the mitogen-activated protein kinase (MAPK) pathway and regulating extracellular matrix (ECM) degradation protease to inhibit the invasion and activity of lung cancer cells. This evidence concerns the gene WNK2 and lung cancer.