PNMA2 (paraneoplastic Ma antigen 2) is a gag-like protein predominantly expressed in the central nervous system that functions as a regulator of cell proliferation, apoptosis, and immune responses 1. Structurally, PNMA2 is derived from a domesticated Ty3 retrotransposon and forms icosahedral non-enveloped virus-like capsids that are released from cells as extracellular antigens 23. Mechanistically, PNMA2 promotes anti-apoptotic signaling and inhibits autophagy through protein-protein interactions; knockdown of PNMA2 enhances apoptosis and reduces cell proliferation and migration 1. PNMA2 antagonizes pro-apoptotic functions of other PNMA family members (PNMA1 and MOAP-1) through heterodimeric interactions 4. Additionally, PNMA2 mediates apoptosis resistance in neural stem cells and may contribute to effects of prenatal alcohol exposure 5. Clinically, PNMA2 is associated with paraneoplastic neurological syndromes, where its capsid structure triggers autoimmune responses with autoantibodies preferentially binding spike epitopes, resulting in neurological deficits 2. PNMA2 is upregulated in endometriosis and achalasia and serves as a potential diagnostic biomarker and therapeutic target 16. The engineered PNMA2 capsids show promise as mRNA delivery vehicles for therapeutic applications 3.