MTOR and hepatocellular carcinoma: Similarly, vascular invasion rate was also observed to be higher in samples with both overexpression of RHEB and EIF5 than in the remaining 87 samples (P = 0.007, 80.6 vs. 56.3%, Table 1), indicating that the activation of mTOR signaling pathway by circRNA-100338 could result in high probability of pulmonary metastasis and/or vascular invasion, further suggesting that the mTOR signaling pathway activated by circRNA-100338/miR-141-3p/RHEB may promote HCC pulmonary metastasis.