TLR7 and Carcinoma, Lewis Lung: In a different experimental setting, by using a syngeneic Lewis lung carcinoma (LLC) cell system in C57BL/6 mice, Dr. Cremer’s group was able to demonstrate that the pro-tumorigenic role of TLR7 depends on its expression on cancer cells and on the recruitment of myeloid-derived suppressor cells (MDSCs) infiltrating the tumor [50].