WNK2 and acute promyelocytic leukemia: In current studies, As2O3 has shown substantial efficacy in treatment of patients with newly diagnosed or relapsed acute promyelocytic leukemia (APL) and other type of cancer and those characterized by the proliferation of immature immune cells, due to its substantial ability to induce apoptosis and mitogen activated protein kinase (MAPK) expression (Zhang et al., 2001).