Elevated RSK4 expression was significantly correlated with the following established markers of disease progression: muscularis propria invasion (P < 0.001), high tumor grade (P < 0.01), advanced TNM stage (P < 0.001), lymph node metastasis (P < 0.01), and distant metastasis (P < 0.05). This evidence concerns the gene RPS6KA6 and metastasis.