TLR3 and lung carcinoma: It is conceivable that as long as a cancer cell (e.g. A549, NCI-H292, and NCI-H358) expresses a low-to-medium level of functional TLR3 protein, it will engage polyI:C and becomes responsive to polyI:C treatment, which activates the TLR3 signalling to subsequently kill the lung carcinoma.