TLR4 and gastric neoplasm: In addition, both the onset of emphysema in Tlr4−/− mice and the TLR2-driven gastric tumour mouse model occurs independent of hematopoietic-derived immune cells [3], [36], which suggests the essential role for Mal by TLR2 and TLR4 may be more restricted to immune cells (e.g. macrophages) rather than non-immune (e.g. lung endothelial, gastric epithelial) cells.