Stat3 decoy oligonucleotide inhibited the expression of IL-6 and IL-10 mRNA [40] and Stat3 siRNA decreased the expression of IL-6, IL-10 and VEGF in melanoma cells [25], while the introduction of Stat3 siRNA did not inhibit Cox-2-induced IL-6 expression in the lung cancer cell A549 [41] and inhibition of Stat3 using antisense oligonucleotide and dominant-negative form of Stat3 in mouse cancer cells increased the expression of IL-6 [29]. This evidence concerns the gene IL10 and lung cancer.