MTOR and esophageal squamous cell carcinoma: Moreover, Shi et al. also declared that high level of circ_0006168 level was positively correlated with TNM stage and lymph node metastasis in the patients with ESCC, and circ_0006168 facilitated the growth and metastasis of ESCC cells via sponging miR-100 and regulating mTOR [16].