A diurnal pattern of TRPV1 mRNA reappeared in the patients with Grades B-D GERD (Fig. 2E, P < 0.001); however, this pattern was changed toward a lower level in the morning and a higher level in the afternoon (Fig. 2E, P < 0.001), so that the expression levels of TRPV1 mRNA in the subjects with Grades B-D GERD in the morning were lower than those in the patient controls and those in the patients with Grade A GERD (Fig. 2E, P < 0.001). This evidence concerns the gene TRPV1 and gastroesophageal reflux disease.