TLR4 and neoplasm: In acute monocytic leukemia, malignant monocytic cells undergo apoptosis in a TLR4-dependent manner.358 Moreover, Bacillus Calmette-Guérin (BCG) can directly induce apoptosis in urothelial carcinoma cells by activating TLR7.359 Interestingly, in vitro experiments have shown that the activation of TLR4 in lung cancer cells can inhibit TNF-α or TRAIL-induced apoptosis via the NK-κB pathway.360 This suggests that the induction of tumor cell apoptosis by TLRs is dependent on the type of tumor.