Expression of miRNA-21in NSCLC and its correlation with prognosis of patients. A, miRNA-21 expression in NSCLC cancer patients detected by real-time RT-PCR. MiRNA-21 expression level was higher in NSCLC tissue than in corresponding non-cancerous tissue. (p<0.0001). U6 snRNA was used as an internal control. Horizontal line, mean value of each group. *** p<0.0001. B, Kaplan-Meier survival curve of NSCLC patients sub-grouped as miRNA-21 low or high expression. The prognosis of patients with high miRNA-21 was significantly shorter than that of patients with miRNA-21 low patients (p=0.007).