PIK3R2 (phosphoinositide-3-kinase regulatory subunit 2) functions as a regulatory subunit of the phosphoinositide-3-kinase (PI3K) complex that phosphorylates phosphatidylinositol 4,5-bisphosphate to generate PIP3, a crucial second messenger in cellular signaling 1. Unlike its paralog PIK3R1 which acts as a tumor suppressor, PIK3R2 functions as an oncogene and is frequently overexpressed in various cancers 23. The protein promotes cell proliferation, survival, and growth through activation of the PI3K/AKT signaling pathway 45. PIK3R2 can interact with phosphorylated EphA2 to facilitate downstream GSK3Ξ²/Ξ²-catenin signaling and promote epithelial-mesenchymal transition in cancer cells 6. Activating mutations in PIK3R2, particularly the recurrent p.G373R mutation, cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome, characterized by brain overgrowth, seizures, and developmental abnormalities 178. The p.G373R mutation results in PI3K pathway hyperactivation, leading to increased cell size rather than cell number in affected brain tissue 7. PIK3R2 also serves as a target for miR-126-3p regulation and plays roles in angiogenesis and cell survival 5.