PPM1D and type 2 diabetes mellitus: The oncoprotein Wip1 is an inhibitor for p38 MAPK; interestingly, wild-type p53-inducible phosphatase 1 (Wip1) knockout induces insulin resistance in mice, whereas Wip1 induction reduces p38 MAPK activation, increasing in turn β-cell proliferation, thus providing a new line of investigation as a possible candidate target also for T2D innovative therapeutic approaches [90,91].