We tested the expression of STAT3 in several cell lines by Western blot, and found that the expression of pSTAT3 in lung cancer lines (SPC-A-1, EKVX, HCC827, H1975, H292, A549, 95D, and L78) was higher than in normal bronchial epithelial (HBEpiC, Beas-2B, 16HBE) or lung fibroblast (HLF) cell lines (Figure 5A). Here, STAT3 is linked to lung cancer.