Consistent with its role as a tumor suppressor, PP2A plays a critical role in the regulation of cell-cycle progression, survival, and differentiation by negatively regulating the PI3K/AKT pathway [10, 11], and dephosphorylating and inactivating MEK1 and ERK family kinases [12, 13], or decreasing the stability and function of c-MYC transcription factors [14, 15]. The gene discussed is PTPA; the disease is neoplasm.