TLR3 and cancer: To demonstrate the mechanisms through which cancer cells sense cytosolic Poly(I:C) and Poly(dA:dT), we first examined the activation and expression of PKR, TLR3, RIG-I, MDA5, LGP2, and DHX29 stimulated by Poly(I:C) and Poly(dA:dT) in PANC-1 cells.