Importantly, the expression of phospho-STAT3Tyr705 was significantly inversely correlated with the mRNA levels of PTPRK in 26 NSCLC tissues (r = −0.727, p < 0.001, Figures 3(c) and 3(d)), and high expression of phospho-STAT3Tyr705 was positive correlated with lymph node metastasis of patients with NSCLC (p = 0.041) (Table 1). Here, PTPRK is linked to metastatic malignant neoplasm in the lymph nodes.