As shown in Fig. 1c and Additional file 1: Figure S2B, the expressions of STAT3 and EMT markers were enhanced in lymph node positive group with significant correlation to lymph node metastatic status in HNSCC samples, for N-cadherin (X2 = 21.365,p =0.000;R = 0.647, p =0.000), vimentin (X2 = 7.358, p =0.007;R = 0.350, p =0.006), E-cadherin (X2 = 21.609, p =0.000;R = -0.645, p =0.000), β-catenin (X2 = 5.742, p =0.017;R = 0.354, p =0.002). Here, STAT3 is linked to head and neck squamous cell carcinoma.