PIK3CA and colorectal carcinoma: In CRC, the reported crosstalk signaling pathways with abnormally expressed circRNA include phosphatidylinositol 3-kinase (PI3K)/AKT (25), mitogen-activated protein kinases (MAPK) (26), Notch (27), Janus kinase/signal transducers and activators of transcription (JAK/STAT) (28), Hippo/YAP (29), WNT/β-catenin (30), and vascular endothelial growth factor (VEGF) (31).