Receiver Operating Characteristics (ROC) curve and Kaplan–Meier survival analyses of plasma/exo-miR-21 individually to prognose CRC recurrence. (A) ROC and Area Under ROC Curve (AUC) in patients with stage I to III CRC, stratified by the selected cut-off points of exo-miR-21. (B) Disease-free survival (DFS) curve by the Kaplan–Meier survival analysis to discriminate recurrence in patients with stage I to III CRC, stratified by cut-off pointes of exo-miR-21. (C) ROC and AUC in patients with stage IV CRC, stratified by the selected cut-off points of exo-miR-21. (D) Progression-free survival (PFS) curve by the Kaplan–Meier survival analysis to discriminate recurrence in patients with stage IV CRC, stratified by cut-off pointes of exo-miR-21. (E) ROC and AUC in patients with stage I to III CRC, stratified by the selected cut-off points of plasma miR-21. (F) DFS curve by the Kaplan–Meier survival analysis to discriminate recurrence in patients with stage I to III CRC, stratified by cut-off pointes of plasma miR-21. (G) ROC and AUC in patients with stage IV CRC, stratified by the selected cut-off points of plasma miR-21. (H) PFS curve by the Kaplan–Meier survival analysis to discriminate recurrence in patients with stage IV CRC, stratified by cut-off pointes of plasma miR-21.