CTLA4 and central nervous system cancer: With the recent advances in immunotherapy, various immunomodulatory approaches are being evaluated in glioma clinical trials, including antibodies targeting the inhibitory immune checkpoint factors such as programmed death ligand-1 (PD-L1) (nivolumab and pembrolizumab) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) (ipilimumab), oncolytic viruses, peptide vaccine trials, and dendritic cell vaccines to name a few (for a detailed review on immunotherapy see [257]).