PEG3 is a paternally expressed, imprinted gene encoding a C2H2 zinc finger transcription factor with dual roles in development and tumor suppression 1. Functionally, PEG3 mediates apoptosis through p53-dependent pathways and inhibits Wnt/β-catenin signaling by promoting β-catenin degradation via a p53/Siah1-dependent mechanism 2. This transcriptional repressor directly binds promoters of lipogenic genes including ACLY, FASN, IDH1, and HMGCR, regulating lipid metabolism with sex-biased effects 3. In developmental contexts, PEG3 is enriched in growing adrenal cortex tissues and regulates maternal-caring behaviors 45. Disease-wise, PEG3 functions as a tumor suppressor in gliomas; loss of PEG3 expression through promoter hypermethylation correlates with increased tumor grade and enhanced glioma stem cell proliferation 627. Clinically, PEG3 represents a susceptibility locus for cancer and neurobehavioral deficits, with therapeutic potential through demethylating agents that restore expression 1. The gene's imprinted status throughout life and widespread neural expression underscore its importance in maintaining cellular homeostasis.