TLR4 and lung carcinoma: As the currently described short-time tumor-promoting effects of endotoxin detected in vitro and in the subcutaneous tumor model might not reflect the physiological situation exactly, the effects of endotoxin and the potential mechanisms (i.e., TLR4, EGFR, COX-2 activation,) need to be validated in orthotopic lung cancer models, for example, in recently described in situ models using bioluminescence [47, 48].