CTLA4 and neoplasm: Numerous clinical trials have aimed to invigorate anti-tumor immunity through targeting immune checkpoint inhibitors (ICI) which target programmed cell death protein-1 (PD-1) (nivolumab and pembrolizumab), PD-L1 (atezolizumab and durvalumab), or T lymphocyte-associated antigen 4 (CTLA-4) (ipilimumab).10–16 Unfortunately, these ICI strategies have not shown therapeutic efficacy in GB patients.17,18 More recently, preclinical studies have utilized adeno-associated virus (AAV) vectors to promote anti-tumor immunity.