To find the potential correlation between lncRNA CASC7 and oesophageal cancer we analysed the GEPIA database, and we found that lncRNA CASC7 was highly expressed in a variety of tumour tissues compared with normal tissues, and the expression of lncRNA CASC7 was particularly high in oesophageal cancer compared to other tumours (Fig. 1A). The gene discussed is AGO2; the disease is carcinoma of esophagus.