GSK3B and esophageal squamous cell carcinoma: We reported previously that circGSK3β promoted ESCC cell migration and invasion via direct interaction with GSK3β and inhibiting GSK3β activity [16], while hsa_circ_0006948 enhances ESCC progression and epithelial-mesenchymal transition through the miR-490-3p sponging [17], indicating that circRNAs are involved in ESCC progression and metastasis.