PHLPP2, short for PH domain and leucine rich repeat protein phosphatase 2, is a member of the PHLPP family of phosphatases. It is known to suppress cell growth, either by inhibiting proliferation or promoting apoptosis. It functions through multiple pathways, such as dephosphorylating key kinases. For instance, it has been identified as the Akt Ser473 phosphatase, and also targets the energy-sensing AMP-activated protein kinase (pAMPK) under metabolic stress [1,2].

In adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice, reduced adiposity and improved whole-body glucose tolerance were observed when fed a high-fat diet. This is due to increased HSL phosphorylation, leading to enhanced lipolysis, and increased PPARα-dependent adiponectin secretion, which ameliorates obesity-induced fatty liver [1]. In T-leukemia cells with glucose limitation, silencing PHLPP2 protein expression prolongs cell survival by promoting a switch to AMPK-mediated fatty acid oxidation [2]. In prostate cancer, complete loss of Phlpp2 in a genetically engineered mouse model blocks prostate tumor growth, as Phlpp2 is essential for supporting Myc, a key driver of lethal prostate cancer [3].

In conclusion, PHLPP2 plays a crucial role in various biological processes and disease conditions. Through gene knockout models, its functions in metabolism-related diseases like obesity-induced fatty liver and in cancer progression have been revealed. These studies help in understanding the underlying molecular mechanisms and may provide potential therapeutic targets for related diseases.