This is of particular interest in the context of TLR4 research, as PD-L1 has also been shown to block the cytolytic activity of PD-1+ tumor infiltrating CD4+ and CD8+ T cells, which are reliant on dendritic cell -TLR4 interaction (Brahmer et al. 2012; Fife et al. 2009). This evidence concerns the gene TLR4 and neoplasm.