Expression levels of CB1 mRNA in the esophagus of the patient controls were similar to those in the subjects with Grade A GERD (Fig. 2A, P > 0.05), but the levels in the subjects with Grades B-D were elevated significantly in the both the morning and the afternoon (Fig. 2A, P < 0.001). The gene discussed is CNR1; the disease is gastroesophageal reflux disease.