CNTNAP2 and carcinoma of esophagus: We further used bioinformatics analysis to identify the hub genes of hypopharyngeal carcinoma with or without esophageal carcinoma, suggesting that GABRG2, CACNA1A, CNTNAP2, NOS1, and SCN4B genes may be potential molecular markers for indicating the risk of hypopharyngeal carcinoma co-occurring with esophageal carcinoma.