SMAD7 and esophageal squamous cell carcinoma: There were 15 circRNAs involved, of which 10 (circ‐DLG1, circ‐TTC17, Circ‐SLC7A5, hsa circ 0000437, hsa circ 0004771, CiRS‐7, circrna_100876, hsa_circ_0006948, hsa_circ_0006168, and has_circ_0067934) were upregulated in ESCC, acting as oncogenes, and five (hsa_circ_0001946, hsa_circ_0062459, circ‐SMAD7, hsa_circ_0001946, and CircVRK1) tumor‐suppressive genes were downregulated.