IGF1R and esophageal squamous cell carcinoma: Therefore, according to the sub-network, we suspected that some circRNA–miRNA–mRNA axes, such as hsa_circRNA_007624–hsa-miR-1290–ESR1, hsa_circRNA_100053–has-let-7c–ESR1/IGF1/IGF1R, and hsa_circRNA_100053–hsa-miR-630–ESR1/TP53BP1/IGF1R/FOXO3, indicated a competitive interaction network of circRNAs in ESCC.