WNK2 and neoplasm: Exosomes produced from tumor cells have been found to stimulate tumor growth by directly activating signaling mechanisms such as phosphorylated phosphatidylinositol 3-kinase/protein kinase B (P13K/AKT) or mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), which are responsible for sustaining the tumor proliferation [64–68].