PPP2R2A appears to be a tumor suppressor gene that is frequently absent or under-expressed in most human tumors, such as prostate cancer, ovarian cancer, acute myelocytic leukemia (AML), and breast cancer [26, 49–53], pointing that PPP2R2A may play a role in tumorigenesis. The gene discussed is PPP2R2A; the disease is acute myeloid leukemia.