CD274 and central nervous system cancer: Recent studies have highlighted the intricate interplay between protein programmed death-1 (PD-1) and the programmed cell death ligand (PD-L1) in the pathogenesis of low-grade gliomas where various receptors such as the EGFR, Toll-like receptor (TLR), and interferon-alpha (IFN-α) receptor induce the expression of PD-L1 [59,60,61,62].