PPM1D and neoplasm: The PPM1D gene (also known as WIP1) encodes wild-type p53-induced phosphatase 1 protein, a negative regulator in the p53 signaling pathway, which has an important role in cellular stress responses, the regulation of the cell cycle and the metabolism of tumor cells, exerting its oncogenic function in various cancer forms by enhancing cell proliferation (see for a review [33,34] and references therein).