The expressions of PRL-3 and RhoC are higher in the higher TNM stage and lymphatic metastasis and pleural metastasis cases, and closely correlate with each other in NSCLC, which suggests that PRL-3 and RhoC might be in the same signal pathway and PRL-3 might promote the distant metastasis of cancer cell by RhoC and downstream factors. This evidence concerns the gene PTP4A3 and cancer.