Functional validation used a single OPCML small interfering RNA (siRNA) with a non-targeting siRNA control (siNC) in U87 and U251 cells with Transwell invasion, wound healing, colony formation, CCK-8 proliferation, and Western blotting for p-AKT and p-mTOR, with LY294002 rescue...Loss of OPCML aligns with proliferative programs and a GBM-specific immune pattern. These data nominate OPCML as a prognostic marker and a surface-level modulator that could be leveraged alongside RTK/PI3K axis inhibitors in GBM.