PIK3C2B is a Class II phosphatidylinositol 3-kinase that phosphorylates phosphatidylinositol (PtdIns) and phosphatidylinositol-4-phosphate (PtdIns4P), with preference for PtdIns, but does not phosphorylate PtdIns(4,5)P2 123. The enzyme generates phosphatidylinositol-3-phosphate (PI(3)P) and functions in phosphatidylinositol-mediated signaling cascades, including potential involvement in EGF and PDGF signaling 1. Mechanistically, PIK3C2B operates in multiple cellular processes. It associates with clathrin and participates in senescent tumor cell engulfment through dynamic PI(3)P generation at prey cell membranes 4. The gene is regulated by transcription factor YY1 and is subject to epigenetic control via polycomb/trithorax responsive elements, suggesting concentration-dependent activation or repression 5. Clinically, PIK3C2B dysregulation associates with multiple malignancies. In bladder cancer, ELF3 mutations correlate with PIK3C2B overexpression 6. In gastric cancer, METTL1-WDR4-mediated m7G modifications enhance PIK3C2B mRNA stability, promoting migration and proliferation through AKT pathway activation 7. PIK3C2B mutations significantly influence progression-free survival in newly diagnosed multiple myeloma 8. Additionally, higher PIK3C2B expression in H1N1-specific B-cells associates with reduced influenza vaccine immunogenicity in HIV-infected children 9.